function changeFocus(obj, evt) {
	if (!isSystemKey(evt) && !isArrow(evt))    
	    if (obj.value.length == obj.maxLength)
		    for (i = 0; i < obj.form.elements.length; i++)
		    if (obj.form.elements[i].tabIndex == obj.tabIndex + 1) {
		    obj.form.elements[i].focus();
		    if (obj.form.elements[i].type == "text")
			    obj.form.elements[i].select();
		    break;
	    }
}

function isNumber(evt, isValue) {
	var charCode;

	if (isSystemKey(evt) || isArrow(evt)) return true;

	if (isValue) {
		charCode = evt;
	} else {
		evt = (evt) ? evt : window.event
		charCode = (evt.which) ? evt.which : evt.keyCode
	}

	return ((charCode >= 48 && charCode <= 57));
}

function isSystemKey(evt) {
    evt = (evt) ? evt : window.event
	var charCode = (evt.which) ? evt.which : evt.keyCode
	switch (charCode) {
		case 13:  //Enter
		case 9:    //Tab 
		case 27:  //Esc
		//case 32:  //Space
		case 8:    //BackSpace
		case 16:  //Shift
		case 17:  //Ctrl
		case 18:  //Alt
		case 20:  //CapsLock
		case 144:  //NumLock
			return true;
			break
		default:
			return false;
	}
}

function isArrow(evt) {
	evt = (evt) ? evt : window.event
	var charCode = (evt.which) ? evt.which : evt.keyCode

	return (charCode >= 37 && charCode <= 40);
		
}