function check(){
  var ext = document.pic_upd.upd.value;
  ext = ext.substring(ext.length-3,ext.length);
  ext = ext.toLowerCase();
  if(ext != 'jpg') {
	  var ext = document.pic_upd.upd.value;
	  ext1 = ext.substring(ext.length-4,ext.length);
	  ext2 = ext.substring(ext.length-3,ext.length);
	  ext1 = ext1.toLowerCase();
  	  ext2 = ext2.toLowerCase();
	  if((ext1 != 'jpeg') && (ext2 != 'jpg') && (ext2 != 'gif') && (ext2 != 'png')) {
		document.getElementById("upd").value='';
    	alert('image format not supported');
		document.pic_upd.upd.value=null;		 
		document.pic_upd.upd.focus();
		return false;
		exit();
  	  }
  	  else{
   		return true; 
		exit();
  	  }
  }	  
  else{
    return true; 
	exit();
  }
}
/**/
function check_file(){
	if(document.pic_upd.upd.value==""){
		alert("Please select an image");
		document.pic_upd.upd.value="";
		document.pic_upd.upd.focus();
		return false;
	}
	else{
		if(check()){
			return true; 
			exit();
		}
		else{
			return false;
			exit();
		}
	}
}