function imposeMaxLength(Object, MaxLen)
{
  return (Object.value.length < MaxLen);
}
function switchDis( val ) 
{ 
 if( val == "18" ) 
 	document.getElementById("jaarselect").disabled=false; 
 else
 	document.getElementById("jaarselect").disabled=true;
		
 if( val == "15" )
 	document.getElementById("maandselect").disabled=false;
 else
 	document.getElementById("maandselect").disabled=true;
	
 if( val == "14" )
 	document.getElementById("eenmaligselect").disabled=false;
 else
 	document.getElementById("eenmaligselect").disabled=true;
}