var ie4 = (document.all);
var nn6 = (document.getElementById && navigator.appName == "Netscape");
var nn4 = (document.layers);

/**
 * Check if key pressed is digit key 0-9
 * must be invoked in keypressed event handler for <input type="text"/> or
 * <textarea> elements
 */
function isDigit(e) {
var c;
var v;
if(ie4) {
v = event.keyCode;
}
else {
v = e.which;
c = String.fromCharCode(v);
}

if(v==0 || v==8) { // enable backspace & cursor keys
	return true;
}
else {
	c = String.fromCharCode(v);
	if(c>='0' && c<='9') {
	return true;
	}
}
return false;
}

/**
 *Similar to isDigit but validates if entered value is a float number (may
 * contain no more than one decimal point)
 */
function isNumFloat(e, el) {
var c;
var v;
if(ie4) {
v = event.keyCode;
}
else {
v = e.which;
c = String.fromCharCode(v);
}

if(v==0 || v==8) { // enable backspace & cursor keys
	return true;
}
else {
	c = String.fromCharCode(v);
	if(c>='0' && c<='9') {
	return true;
	}
	else if(c == '.') {
	s = new String(el.value);
	if(s.indexOf('.') == -1) {
		return true;
	}
	}
}
return false;
}

function isNumFloatD(e, el) {
	var c;
	var v;

	if(ie4) {
		v = event.keyCode;
	}
	else {
		v = e.which;
		c = String.fromCharCode(v);
	}

	if(v==0 || v==8) { // enable backspace & cursor keys
		return true;
	}
	else {
		if(el.value.indexOf('.') != -1){
			var str = el.value.substr(el.value.indexOf('.') + 1);
			if(str.length > 2) return false;
		}

		c = String.fromCharCode(v);
		if(c>='0' && c<='9') {
			return true;
		}
		else if(c == '.') {
			s = new String(el.value);
			if(s.indexOf('.') == -1) {
				return true;
			}
		}
	}
	return false;
}