count = 0;

function OnCheckboxClick(id, checked, FormId) {
	if(FormId == null) FormId = 0;
//	document.forms[FormId].getElementById("but_"+id).disabled = !checked;
	document.forms[FormId]["but_"+id].disabled = !checked;
	(checked ? count++ : count--); 
	document.forms[FormId].butDelete.disabled = !count;

}