anchor.diff:  		    document.getElementById("file_input").onchange = function(){
   		        var files = document.getElementById("file_input").files;
   		        var file = files[0];
  -		        console.log(file.type);
  -
   		        if(file == null){
  -
   		            alert("No file selected.");
   		        }
   		        else if(file.size > 3000000) {
  
positive.code: 		})();
  		function get_signed_request(file){
  		    var xhr = new XMLHttpRequest();
  		    xhr.open("GET", "/sign_s3?file_name="+file.name+"&file_type="+file.type);
  		    xhr.onreadystatechange = function(){
  		        if(xhr.readyState === 4){
  		            if(xhr.status === 200){
  
negative.code: 		    };
  		    xhr.onerror = function() {
  		        alert("Could not upload file.");
  		    };	
  		    xhr.send(file);
  		}