var submitcount=0;
function checksubmit() {               
      if (submitcount == 0) {
         submitcount++;
         return true;
      } else {
        alert("This form has already been submitted.");
        return false;
      }
 }

function submitFunction() {
   if (validate()) { 
     if (checksubmit()) {
	   document.PostForm.submit();   
	}
   }
 }

function validate(){
  if (PostForm.message.value=="") {
	  alert("A valid comment  is required."); 
	  document.PostForm.message.focus();
	   return false;
  }  
  if (PostForm.sender.value=="") {
      alert("A valid Name is required."); 
	  document.PostForm.sender.focus();
	   return false;
  }   
  return true; 
}

function newwin2(w,wd,h,s) { 
  winny=window.open(w,'theWindow','toolbar=0,status=0,scrollbars='+s+',resizable=0,width='+wd+',height='+h+'');        
  winny.focus() 
}