function validateLoginNull(obj)
{
	if ((IsEmpty(obj.document.frmLogin.txtUsername))&&(IsEmpty(obj.document.frmLogin.txtPassword)))
   { 
      alert('Please enter your username & password to login.') 
      obj.document.frmLogin.txtUsername.focus(); 
      return false; 
   } 
	if(IsEmpty(obj.document.frmLogin.txtUsername)) 
   { 
      alert('Please enter your username.') 
      obj.document.frmLogin.txtUsername.focus(); 
      return false; 
   } 
   if(IsEmpty(obj.document.frmLogin.txtPassword)) 
   { 
      alert('Please enter your password.') 
      obj.document.frmLogin.txtPassword.focus(); 
      return false; 
   }    
	return true;
} 

function validateSearchNull(obj)
{
   if(IsEmpty(obj.document.frmSearch.txtSearch)) 
   { 
      alert('Please enter a search word or phrase.') 
      obj.document.frmSearch.txtSearch.focus(); 
      return false; 
   } 
	return true;
} 

function IsEmpty(aTextField) {
   if ((aTextField.value.length==0) ||
   (aTextField.value==null)) {
      return true;
   }
   else { return false; }
}