jquery - Unable to submit form using Javascript -

i trying submit form named 'vform' using javascript , ajax.here button named 'show' being used show 'div' containing form named vform , form calls codevalidate function , there submits form using ajax code..where getting error vform.submit().here's html , js code(i know error in if condition not know where)

html:

<button id="show" onclick="javascript:codefield(); return false";>apply discount</button>             <div id="apply" style="display:none">voucher code<br>             <form id="vform" name="vform" action="" method="post" onsubmit="javascript:codevalidate(); return false;" >             <input type="text" name="code" id="code"><br>             <span id="error" style="color:red"></span><br>             <input type="submit" name="btn" value="apply" id="btn" ></form>             </div> 

javascript:

function codevalidate() {  if(document.getelementbyid('code').value!=="") { $.post("couponajax.php",{code:$("#code").val()},     function(data)     {            if(data=='1')         {             //alert("success");             vform.submit();             return true;         }         else          {             document.getelementbyid('error').innerhtml="you have entered wrong code!";             return false;         }      });  } else { document.getelementbyid('error').innerhtml="code can't empty!"; return false; }  return false; 

}

codefield function displaying div on onclick event , ajax call checking whether code exists in database or not..if exists returns 1 else 0. problem alert message being displayed form not being submitted. how can fix problem?

i think missing jquery selector.

try replace

 vform.submit(); 

with

$("#vform").submit();  

or can call submit button click event like

$("#btn").click();