var ie = document.all? true : false;
var moz = document.getElementById && !document.all ? true : false;

function getObject(nameStr) {
	if (moz) {
    	return document.getElementById(nameStr);
    }
    else if (ie) {
        return document.all[nameStr];
    }
}

function isNumeric(value) {
	if (isNaN(value))
		return 0;
	else
		return value;
}

function addVal(inputName, step, max) {
	spinInput = getObject(inputName);
	currentVal = parseInt(isNumeric(spinInput.value));
	if(currentVal >= parseInt(max)){spinInput.value = max;return;}
	spinInput.value = currentVal + parseInt(step);

}
function subVal(inputName, step,min) {
	spinInput = getObject(inputName);
	currentVal = parseInt(isNumeric(spinInput.value));
	if(currentVal <= parseInt(min)){spinInput.value = min;return;}
	spinInput.value = currentVal - parseInt(step);
}