onSubmit="return... fonksiyonunda alert yerine ajax div kullanmak?

<form name="people_search" [B]onSubmit="return checkmyform();"[/B] action="people_directory.php" method="post">

<script type="text/javascript">
<!--
function checkmyform ()
{
    var error = "";
    var returnval;

    if (document.people_search.FirstName.value == "") {
      error = error + " FirstName";
    }
    if (document.people_search.LastName.value == "") {
      error = error + " LastName";
    }
    if (error.length > 0)
    {
        alert("Please enter the following fields: " + error);
        document.people_search.focus();
        returnval = false;
    }
    else
    {
        returnval = true;
    }
    return returnval;
}
//-->
</script>

<SCRIPT language=javascript>
<!--
function uyelik_onsubmit(){
  if (document.uyelik.T10.value == ""){
        document.getElementById("bilgi").innerHTML = "<b><font face='Verdana' style='font-size: 10pt' color='#000000'>İsim yazınız!</font></b>";
        document.uyelik.T10.focus();
        return false;  
      }
}
//-->
</SCRIPT>

<form name=uyelik method=post onsubmit="return uyelik_onsubmit()">
</form>