// ==========================================================
function lettersOnly(obj, evt, mode, spaces) {
	var rx = "^[";
	switch( mode ) {
		case "ucase":
			rx += "A-Z";
			break;
		case "lcase":
			rx += "a-z";
			break;
		default:
			rx += "A-Za-z";
			break;
	}
	if( spaces == "true" ) {
		rx += " ";
	}
	rx += "]*$";
	KT_num_rx = new RegExp(rx);
	
	// full regexp is /^[A-Za-z ]*$/
	if (!obj.value.match(KT_num_rx)) {
		if (obj.lastMatched) {
			obj.value = obj.lastMatched;
		} else {
			obj.value = "";
		}
	} else {
		obj.lastMatched = obj.value;
	}
}

// ==========================================================
function numbersOnly(obj, evt, negative, afloat) {
	var rx = "^";
	if( negative == "true" ) {
		rx += "-?";
	}
	rx += "[0-9]*";
	if( afloat == "true" ) {
		rx += "\\.?[0-9]*";
	}
	rx += "$";
	KT_num_rx = new RegExp(rx);
	
	// full regexp is /^-?[0-9]*\.?[0-9]*$/
	if( !obj.value.match(KT_num_rx) ) {
		if( obj.lastMatched ) {
			obj.value = obj.lastMatched;
		} else {
			obj.value = "";
		}
	} else {
		obj.lastMatched = obj.value;
	}
}

// ==========================================================
function editMaskPre(obj, mask, evt) {
	var keyCode = evt.keyCode;
	if (keyCode == 0) {
		keyCode = evt.charCode;
	}
	if (obj.value.length == 0 && keyCode != 8 && keyCode != 0 && keyCode!= 9) {
		completeMask(obj, mask);
	}
}

// ==========================================================
function toRegEXP(txt) {
	txt = txt.replace(/([-\/\[\]()\*\+])/g, '\\$1');
	txt = txt.replace(/N/g, '\\d');
	txt = txt.replace(/\?/g, '.');
	txt = txt.replace(/A/g, '\\w');
	txt = txt.replace(/C/g, '[A-Za-z]');
	return txt;
}

// ==========================================================
function editMask(obj, mask, evt) {
	var tmVal = getFirstMatch(obj.value, mask);
	if (obj.value != tmVal) {
		obj.value = tmVal;
	}
	if(evt.keyCode != 8 && obj.value.length != 0) { // backspace and tab
		completeMask(obj, mask);
	}
}

// ==========================================================
function getFirstMatch(value, mask) {
	var size = value.length;
	if(size == 0) {
		return "";
	}
	var re = new RegExp('^' + toRegEXP(mask.substr(0, size)) + '$');
	if (!value.match(re)) { 
		return getFirstMatch(value.substr(0, size-1), mask);
	} else {
		return value;
	}
}

// ==========================================================
function completeMask(obj, mask) {
	var size = obj.value.length;
	var sw=true;
	var tmp = obj.value;
	while (sw) {
		if (mask.length<=size) {
			break;
		}
		switch (mask.charAt(size)) {
			case 'N':
			case 'A':
			case 'C':
			case '?':
				sw = false;
				break;
			default:
				tmp += mask.charAt(size);
		}
		size++;
	}
	if (obj.value != tmp) {
		obj.value = tmp;
		obj.lastMatched = obj.value;
	}
	return;
}