Question

I’m trying to get this field (Order Cost) to update when I change the Quantity to reflect the new cost (Qty * Price)

<td class="result" align="right">$<Input type="text" maxLength="9" style="text-align:right; width:55px;" align="right" id="OC<%=i %>" value="<%=formatnumber(rstBevInventory("avg_unit_cost"),2)*proposed %>"/></td>

It calculates the original total, but when I change the Qty, it calls this Javascript function:

function reCalcOrder(i){
    document.getElementById("OC"+i).value = document.getElementById("P"+i).value * document.getElementById("Q"+i).value;
    cost = document.getElementById("OC"+i).value;
    Math.round(cost * 100) / 100;
    document.getElementById("OC"+i).set("value", "cost");
        if (document.getElementById("Q"+i).value < 0){
            document.getElementById("Q"+i).value = 0;
        }
}

I get way too many digits, and it seems like this is because of the way Javascript handles multiplication. Is there a way to have the ASP react when the Qty field is changed? Because ASP seems to do the math without issue.

Thanks ahead of time!

Answer 1

Yes, there is, using Ajax. But I believe you’ll also fix if the problem if you change this line:

Math.round(cost * 100) / 100;

to

cost = Math.round(cost * 100) / 100;

Another option is using Number.prototype.toFixed:

cost = cost.toFixed(2);