function isEmpty(obj)
{
	try {
		if ( obj.type == 'text' || obj.type == 'textarea' || obj.type == 'password' || obj.type == 'hidden' ) {
			val = obj.value;
			do {
				val = val.replace(' ', '');
			} while ( val.search(' ') != -1 );
			if ( !val ) {
				return true;
			} else {
				return false;
			}
		} else if ( obj.type == 'select-one' ) {
			if ( obj.selectedIndex <= 0 )	return true;
			return false;
		} else if ( obj.type == 'select-multiple' ) {
			sel = 0;
			for ( i=0; i<obj.length; i++ ) {
				if ( obj.options[i].selected )	sel = 1;
			}
			if ( sel )	return false;
			else		return true;
		} else {
			//radio ou checkbox
			if ( obj.length ) {
				sel = 0;
				for ( i=0; i<obj.length; i++ )
					if ( obj[i].checked )	sel = 1;
				if ( sel==0 )	return false;
				else		return true;
			}
		}
	} catch (e) {
		if ( showError )	alert(e.message); 
		return false;
	}
}