File gif,png,jpg,pdf upload check

File gif,png,jpg,pdf upload check

<br /><script language="JavaScript">
<br />function develop_validation()
<br />{
<br />  
<br />  var fileupload3=document.selectdate.fileupload1.value;
<br />  if(fileupload3==""){   
<br />  alert("Please Upload Video");document.selectdate.fileupload3.focus();return false;  
<br />  }   
<br />  		
<br />	if(fileupload3 != "" )
<br />	{
<br />	  if (valupfile(fileupload3,"Thumbnail Image should be in jbg or gif or png") == false)
<br />	  {
<br />		   document.selectdate.fileupload3.select();
<br />		   return false;
<br />	  }
<br />	}
<br />	
<br />	
<br />	
<br />   return true;
<br />  
<br />}
<br />
<br />
<br />//function valupfile(field,alerttxt)
<br />//{
<br />//  with (field)
<br />//  {
<br />//   var dotjpg = field.lastIndexOf(".jpg")
<br />//   var dotgif = field.lastIndexOf(".gif")
<br />//   var dotpng = field.lastIndexOf(".png")
<br />//  
<br />//   if(dotjpg >= 0)
<br />//   return true; 
<br />//   else if(dotgif >= 0)
<br />//    return true;
<br />//   else if(dotpng >= 0)
<br />//    return true;
<br />//   else  		
<br />//    {
<br />//	  alert(alerttxt)
<br />//	  return false;
<br />//    }  
<br />//  }
<br />//} 
<br />	
<br />
<br /></script>
<br />
<br />
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