function IsBlank(value) {
   for (var x = value.length - 1; x >= 0; x--) {
      if ((value.charAt(x) != " ") && (value.charAt(x) != "")) {
         return false;
      } 
   }
   return true;
}
function ValidateForm(Logon) {
   
   if ((IsBlank(Logon.username.value))) 
       {
      alert("Please enter User Name");
		document.Logon.username.focus();
     	return false;
   }
   else if ((IsBlank(Logon.password.value)))
   {  alert("Please enter Password");
   		document.Logon.password.focus();                           
        return false;
   }   else {                              
            return true;
   }
   }