function selectAll(objChb , checkedVal)
{
   if(objChb.length)
      for(i = 0; i < objChb.length; i ++ )
		objChb[i].checked = checkedVal;
   else
	  objChb.checked = checkedVal;
}

function validate( objFrm , objChb )
{	
	objChb = objFrm.elements[objChb];	
	if(objChb.length)
	{
		for(i = 0; i < objChb.length; i ++ )
			if ( objChb[i].checked )
				return true;
	}
	else
	{
		if ( objChb.checked )
			return true;
	}
	alert("Please select atleast one checkbox."); 
	return false;
}