diff --git a/dist/cron-ui.min.js b/dist/cron-ui.min.js
index 9ea5ca9..f9346f6 100644
--- a/dist/cron-ui.min.js
+++ b/dist/cron-ui.min.js
@@ -1,2 +1 @@
-// Version: 0.1
-function CronUI(container,opts){if(container instanceof HTMLElement){this.el=container}else if(typeof container==='string'){this.el=document.querySelector(container)}else{throw "CronUI: container parameter in initialization must be an html element or a string selector."}this.options=opts?opts:{};this.render();if(typeof this.options.initial!=='string'){this.options.initial='* * * * *'}this.setCronString(this.options.initial);this.currentValue=this.options.initial}CronUI.prototype.render=function(){var el=this.el;var str_opt_mih="";for(var i=0;i<60;i+=1){var j=(i<10)?"0":"";str_opt_mih+="<option value='"+i+"'>"+j+i+"</option>\n"}var str_opt_hid="";for(var i=0;i<24;i+=1){var j=(i<10)?"0":"";str_opt_hid+="<option value='"+i+"'>"+j+i+"</option>\n"}var str_opt_dom="";for(var i=1;i<32;i+=1){if(i==1||i==21||i==31){var suffix="st"}else if(i==2||i==22){var suffix="nd"}else if(i==3||i==23){var suffix="rd"}else{var suffix="th"}str_opt_dom+="<option value='"+i+"'>"+i+suffix+"</option>\n"}var str_opt_month="";var months=["January","February","March","April","May","June","July","August","September","October","November","December"];for(var i=0;i<months.length;i+=1){str_opt_month+="<option value='"+(i+1)+"'>"+months[i]+"</option>\n"}var str_opt_dow="";var days=["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];for(var i=0;i<days.length;i+=1){str_opt_dow+="<option value='"+i+"'>"+days[i]+"</option>\n"}var str_opt_period="";var periods=["minute","hour","day","week","month","year"];for(var i=0;i<periods.length;i+=1){str_opt_period+="<option value='"+periods[i]+"'>"+periods[i]+"</option>\n"}var blocks={};el.insertAdjacentHTML('beforeend',"<span class='cron-period'><select>"+str_opt_period+"</select></span>");var periodEl=el.querySelector('.cron-period select');periodEl.addEventListener("change",this.periodChanged.bind(this));periodEl.addEventListener("change",this.changeEvent.bind(this));el.insertAdjacentHTML('beforeend',"<span class='cron-block cron-block-dom'> on the <select name='cron-dom'>"+str_opt_dom+"</select> </span>");blocks["dom"]=el.querySelector('.cron-block-dom');el.insertAdjacentHTML('beforeend',"<span class='cron-block cron-block-month'> of <select name='cron-month'>"+str_opt_month+"</select> </span>");blocks["month"]=el.querySelector('.cron-block-month');el.insertAdjacentHTML('beforeend',"<span class='cron-block cron-block-mins'> at <select name='cron-mins'>"+str_opt_mih+"</select> minutes past the hour </span>");blocks["mins"]=el.querySelector('.cron-block-mins');el.insertAdjacentHTML('beforeend',"<span class='cron-block cron-block-dow'> on <select name='cron-dow'>"+str_opt_dow+"</select> </span>");blocks["dow"]=el.querySelector('.cron-block-dow');el.insertAdjacentHTML('beforeend',"<span class='cron-block cron-block-time'> at <select name='cron-time-hour' class='cron-time-hour'>"+str_opt_hid+"</select>:<select name='cron-time-min' class='cron-time-min'>"+str_opt_mih+" </span>");blocks["time"]=el.querySelector('.cron-block-time');for(var blockName in blocks){for(var selectEl of blocks[blockName].querySelectorAll('select')){selectEl.addEventListener("change",this.changeEvent.bind(this))}}this.blocks=blocks};CronUI.prototype.periodChanged=function(){var blocks=this.blocks;var cronPeriodEl=this.el.querySelector('.cron-period select');var period=cronPeriodEl.options[cronPeriodEl.selectedIndex].value;for(var blockName in blocks){blocks[blockName].style.display='none'}if(CronUI.displayMatrix.hasOwnProperty(period)){var b=CronUI.displayMatrix[period];for(var i=0;i<b.length;i+=1){blocks[b[i]].style.display=''}}};CronUI.prototype.changeEvent=function(){this.currentValue=this.getCronString();if(typeof this.options.changeEvent==='function'){this.options.changeEvent(this.currentValue)}};CronUI.prototype.getCronString=function(){var min,hour,day,month,dow;min=hour=day=month=dow="*";var blocks=this.blocks;var getSelectValue=function(el){return el.options[el.selectedIndex].value};var selectedPeriod=getSelectValue(this.el.querySelector('.cron-period select'));switch(selectedPeriod){case "minute":break;case "hour":min=getSelectValue(blocks["mins"].querySelector('select'));break;case "day":min=getSelectValue(blocks["time"].querySelector('.cron-time-min'));hour=getSelectValue(blocks["time"].querySelector('.cron-time-hour'));break;case "week":min=getSelectValue(blocks["time"].querySelector('.cron-time-min'));hour=getSelectValue(blocks["time"].querySelector('.cron-time-hour'));dow=getSelectValue(blocks["dow"].querySelector('select'));break;case "month":min=getSelectValue(blocks["time"].querySelector('.cron-time-min'));hour=getSelectValue(blocks["time"].querySelector('.cron-time-hour'));day=getSelectValue(blocks["dom"].querySelector('select'));break;case "year":min=getSelectValue(blocks["time"].querySelector('.cron-time-min'));hour=getSelectValue(blocks["time"].querySelector('.cron-time-hour'));day=getSelectValue(blocks["dom"].querySelector('select'));month=getSelectValue(blocks["month"].querySelector('select'));break;default:return selectedPeriod}return[min,hour,day,month,dow].join(" ")};CronUI.prototype.setCronString=function(cronString){var blocks=this.blocks;var cronType=CronUI.getCronType(cronString);if(!cronType){return false}var d=cronString.split(" ");var v={"dom":d[2],"dow":d[4],"hour":d[1],"mins":d[0],"month":d[3]};var targets=CronUI.displayMatrix[cronType];for(var i=0;i<targets.length;i+=1){var tgt=targets[i];if(tgt=="time"){blocks[tgt].querySelector(".cron-time-hour").value=v["hour"];blocks[tgt].querySelector(".cron-time-min").value=v["mins"]}else{blocks[tgt].querySelector("select").value=v[tgt]}}this.el.querySelector('.cron-period select').value=cronType;this.periodChanged();return this};CronUI.displayMatrix={"day":["time"],"hour":["mins"],"minute":[],"month":["dom","time"],"week":["dow","time"],"year":["dom","month","time"]};CronUI.cronTypes={"day":/^(\d{1,2}\s){2}(\*\s){2}\*$/,"hour":/^\d{1,2}\s(\*\s){3}\*$/,"minute":/^(\*\s){4}\*$/,"month":/^(\d{1,2}\s){3}\*\s\*$/,"week":/^(\d{1,2}\s){2}(\*\s){2}\d{1,2}$/,"year":/^(\d{1,2}\s){4}\*$/};CronUI.getCronType=function(cronString){cronString=cronString?cronString:this.getCronString();var valid_cron=/^((\d{1,2}|\*)\s){4}(\d{1,2}|\*)$/;if(typeof cronString!="string"||!valid_cron.test(cronString)){return undefined}var d=cronString.split(" ");var minval=[0,0,1,1,0];var maxval=[59,23,31,12,6];for(var i=0;i<d.length;i+=1){if(d[i]=="*"){continue}var v=parseInt(d[i]);if(v<=maxval[i]&&v>=minval[i]){continue}return undefined}for(var type in CronUI.cronTypes){if(CronUI.cronTypes[type].test(cronString)){return type}}return undefined};
\ No newline at end of file
+function CronUI(e,t){if(e instanceof HTMLElement)this.el=e;else{if("string"!=typeof e)throw"CronUI: container parameter in initialization must be an html element or a string selector.";this.el=document.querySelector(e)}this.options=t?t:{},this.render(),"string"!=typeof this.options.initial&&(this.options.initial="* * * * *"),this.setCronString(this.options.initial),this.currentValue=this.options.initial}CronUI.prototype.render=function(){for(var e=this.el,t="",r=0;60>r;r++){var n=10>r?"0":"";t+="<option value='"+r+"'>"+n+r+"</option>\n"}for(var o="",r=0;24>r;r++){var n=10>r?"0":"";o+="<option value='"+r+"'>"+n+r+"</option>\n"}for(var i="",r=1;32>r;r++){if(1==r||21==r||31==r)var s="st";else if(2==r||22==r)var s="nd";else if(3==r||23==r)var s="rd";else var s="th";i+="<option value='"+r+"'>"+r+s+"</option>\n"}for(var c="",a=["January","February","March","April","May","June","July","August","September","October","November","December"],r=0;r<a.length;r++)c+="<option value='"+(r+1)+"'>"+a[r]+"</option>\n";for(var l="",u=["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"],r=0;r<u.length;r++)l+="<option value='"+r+"'>"+u[r]+"</option>\n";for(var d="",h=["minute","hour","day","week","month","year"],r=0;r<h.length;r++)d+="<option value='"+h[r]+"'>"+h[r]+"</option>\n";var m={};e.insertAdjacentHTML("beforeend","<span class='cron-period'><select>"+d+"</select></span>");var p=e.querySelector(".cron-period select");p.addEventListener("change",this.periodChanged.bind(this)),p.addEventListener("change",this.changeEvent.bind(this)),e.insertAdjacentHTML("beforeend","<span class='cron-block cron-block-dom'> on the <select name='cron-dom'>"+i+"</select> </span>"),m.dom=e.querySelector(".cron-block-dom"),e.insertAdjacentHTML("beforeend","<span class='cron-block cron-block-month'> of <select name='cron-month'>"+c+"</select> </span>"),m.month=e.querySelector(".cron-block-month"),e.insertAdjacentHTML("beforeend","<span class='cron-block cron-block-mins'> at <select name='cron-mins'>"+t+"</select> minutes past the hour </span>"),m.mins=e.querySelector(".cron-block-mins"),e.insertAdjacentHTML("beforeend","<span class='cron-block cron-block-dow'> on <select name='cron-dow'>"+l+"</select> </span>"),m.dow=e.querySelector(".cron-block-dow"),e.insertAdjacentHTML("beforeend","<span class='cron-block cron-block-time'> at <select name='cron-time-hour' class='cron-time-hour'>"+o+"</select>:<select name='cron-time-min' class='cron-time-min'>"+t+" </span>"),m.time=e.querySelector(".cron-block-time");for(var y in m)[].forEach.call(m[y].querySelectorAll("select"),function(e){e.addEventListener("change",this.changeEvent.bind(this))}.bind(this));this.blocks=m},CronUI.prototype.periodChanged=function(){var e=this.blocks,t=this.el.querySelector(".cron-period select"),r=t.options[t.selectedIndex].value;for(var n in e)e[n].style.display="none";if(CronUI.displayMatrix.hasOwnProperty(r))for(var o=CronUI.displayMatrix[r],i=0;i<o.length;i++)e[o[i]].style.display=""},CronUI.prototype.changeEvent=function(){this.currentValue=this.getCronString(),"function"==typeof this.options.changeEvent&&this.options.changeEvent(this.currentValue)},CronUI.prototype.getCronString=function(){var e,t,r,n,o;e=t=r=n=o="*";var i=this.blocks,s=function(e){return e.options[e.selectedIndex].value},c=s(this.el.querySelector(".cron-period select"));switch(c){case"minute":break;case"hour":e=s(i.mins.querySelector("select"));break;case"day":e=s(i.time.querySelector(".cron-time-min")),t=s(i.time.querySelector(".cron-time-hour"));break;case"week":e=s(i.time.querySelector(".cron-time-min")),t=s(i.time.querySelector(".cron-time-hour")),o=s(i.dow.querySelector("select"));break;case"month":e=s(i.time.querySelector(".cron-time-min")),t=s(i.time.querySelector(".cron-time-hour")),r=s(i.dom.querySelector("select"));break;case"year":e=s(i.time.querySelector(".cron-time-min")),t=s(i.time.querySelector(".cron-time-hour")),r=s(i.dom.querySelector("select")),n=s(i.month.querySelector("select"));break;default:return c}return[e,t,r,n,o].join(" ")},CronUI.prototype.setCronString=function(e){var t=this.blocks,r=CronUI.getCronType(e);if(!r)return!1;for(var n=e.split(" "),o={mins:n[0],hour:n[1],dom:n[2],month:n[3],dow:n[4]},i=CronUI.displayMatrix[r],s=0;s<i.length;s++){var c=i[s];"time"==c?(t[c].querySelector(".cron-time-hour").value=o.hour,t[c].querySelector(".cron-time-min").value=o.mins):t[c].querySelector("select").value=o[c]}return this.el.querySelector(".cron-period select").value=r,this.periodChanged(),this},CronUI.displayMatrix={minute:[],hour:["mins"],day:["time"],week:["dow","time"],month:["dom","time"],year:["dom","month","time"]},CronUI.cronTypes={minute:/^(\*\s){4}\*$/,hour:/^\d{1,2}\s(\*\s){3}\*$/,day:/^(\d{1,2}\s){2}(\*\s){2}\*$/,week:/^(\d{1,2}\s){2}(\*\s){2}\d{1,2}$/,month:/^(\d{1,2}\s){3}\*\s\*$/,year:/^(\d{1,2}\s){4}\*$/},CronUI.getCronType=function(e){e=e?e:this.getCronString();var t=/^((\d{1,2}|\*)\s){4}(\d{1,2}|\*)$/;if("string"==typeof e&&t.test(e)){for(var r=e.split(" "),n=[0,0,1,1,0],o=[59,23,31,12,6],i=0;i<r.length;i++)if("*"!=r[i]){var s=parseInt(r[i]);if(!(s<=o[i]&&s>=n[i]))return}for(var c in CronUI.cronTypes)if(CronUI.cronTypes[c].test(e))return c}};
\ No newline at end of file
diff --git a/lib/cron-ui.js b/lib/cron-ui.js
index 4e51e81..7eec5ee 100644
--- a/lib/cron-ui.js
+++ b/lib/cron-ui.js
@@ -128,9 +128,9 @@ CronUI.prototype.render = function() {
     
     // Atttach the change event to all selectors
     for (var blockName in blocks) {
-        for (var selectEl of blocks[blockName].querySelectorAll('select')) {
+        [].forEach.call(blocks[blockName].querySelectorAll('select'), function(selectEl) {
             selectEl.addEventListener("change", this.changeEvent.bind(this));
-        }
+        }.bind(this));
     }
 
     // Save a reference to blocks