function validateAllInput()
{
    var blnAllValid = true;

    blnAllValid &= validateField(document.getElementsByName("txtQty"));

    if (blnAllValid == false)
    {
        window.alert("Shopping cart has invalid item quantities!");
    }

    return blnAllValid;
}

function validateField(oPassed)
{
    var oEl;
    var blnReturn = true;
    var strValue;
    var intCounter


    for (intCounter = 0; intCounter < oPassed.length; intCounter++)
    {
        oEl = oPassed[intCounter];

        strValue = new String(oEl.value);


        if (strValue == null || strValue.length <= 0 || isNaN(strValue) || Number(strValue) < 0)
        {
            oEl.style.backgroundColor = "#FFFF00";
            blnReturn &= false;
        }
        else
        {
            oEl.style.backgroundColor = "#FFFFFF";
            blnReturn &= true;
        }
    }

    return blnReturn;
}