var formname = 'mainform';
var classd = 'input_gray_d';
var classe = 'input_gray';

function iftagdisable(objname, value, disablename, flip) {
	var obj = eval('document.forms.' + formname + '.' + objname);
	var objdisable = eval('document.forms.' + formname + '.' + disablename);
	if (flip) {
		if (obj != value) dis_on(objdisable);
		else dis_off(objdisable);
	} else {
		if (obj == value) dis_on(objdisable);
		else dis_off(objdisable);
	}
}

function dis_on(obj) {
	obj.disabled = true;
	if (obj.type == 'text' || obj.type == 'select-one') {
		obj.className = classd;
		if (obj.type == 'text') obj.value = '';
	}
}

function dis_off(obj) {
	obj.disabled = false;
	if (obj.type == 'text' || obj.type == 'select-one') obj.className = classe;
}