var lowerlimit = 1;
var upperlimit = 10;
var num        = 1;

function setInc()
{
    if (num < upperlimit)
    {
        num++;
        document.getElementById("form1").quantity.value = num;
    }
}
function setDec()
{
    if (num > lowerlimit)
    {
        num--;
        document.getElementById("form1").quantity.value = num;
    }
}
/*
window.onload = function()
{
    // �����l���
    document.getElementById("form1").txt1.value = num;
} */