javascript - html2canavas error in mvc 4 project -

so here im trying do: have page user sees representation of card after user clicks save card following function called , data should return controller in order me save card image. use html2canvas , here code:

<div class="row download-card"> <div class="span12">     <h2>congratulations!</h2>     <h3>you may download mycard</h3>     <div id="card" class="card center">         <ul>             <li style="float: left;position: absolute;display: block;padding-top: 200px; padding-left: 200px;text-align: left;font-family:arial;color:white;font-size:x-large;">@name @lastname<span style="padding-left:90px;font-size:x-large; color:#ffffff;font-family:arial;">@cardno</span></li>             <li style="float: left;position: absolute;display: block;padding-top: 230px; padding-left: 200px;text-align: left;color:white;">member since: @yearregistered <span style="color:white; padding-left:10px;font-family:arial;">valid thru: @validthru</span></li>         </ul>     </div>     <button class="btn" type="button" onclick="screenshot('card')">download</button> </div> </div>  <script src="~/assets/userpanel/js/html2canvas.js"></script> <script type="text/javascript">   function screenshot(id) { html2canvas(id, {     proxy: "https://html2canvas.appspot.com/query",     onrendered: function(canvas) {          var img = canvas.todataurl("image/png");         var output = img.replace(/^data:image\/(png|jpg);base64,/, "");         var output = encodeuricomponent(img);          var parameters = "image=" + output + "&filedir=" + cur_path;         $.ajax({             type: "post",             url: "profile/savecardpng",             data: parameters,             success : function(data)             {                 console.log("screenshot done");             }         }).done(function() {             //$('body').html(data);         });      } }); } </script> 

so button on page calls function screenshot('card') , fires following error in console:

uncaught typeerror: object c has no method 'getelementsbytagname' html2canvas.js:2191 _html2canvas.preload html2canvas.js:2191

(anonymous function)

please let me know whats happening?!

pretty sure html2canvas requires dom element, not string id. try using:

function screenshot(id) {     var elem = document.getelementbyid( id );     html2canvas( elem, {...}); }