Problem with totaling script

I recently posted a script that I had that was adding certain fields to come up with a total only the problem was that it would not work if somebody added in any characters that weren't numbers.  Somebody was very gracious in helping me fix that.  Another problem has come up with the script in that if a number is entered for the price that does not include at least a decimal point at the end, the script actually deletes what the entered into the price field.  Does anybody know of a work around for this?

Here is the script:

<SCRIPT LANGUAGE="JavaScript">
function LoadFuncs() {
if (document.js) initNav();
calculate}
</SCRIPT>
<SCRIPT LANGUAGE="JavaScript">
function dp(price)
{
string = "" + price;
number = string.length - string.indexOf('.');
if (string.indexOf('.') == -1)
return string + '.00';
if (number == 1)
return string + '00';
if (number == 2)
return string + '0';
if (number > 3)
return string.substring(0,string.length-number+3);
return string;
}
function calculate()
{
document.Order.totalA.value = dp((document.Order.Qty_A.value)*(document.Order.Price_A.value))
document.Order.totalB.value = dp((document.Order.Qty_B.value)*(document.Order.Price_B.value))
document.Order.totalC.value = dp((document.Order.Qty_C.value)*(document.Order.Price_C.value))
document.Order.totalD.value = dp((document.Order.Qty_D.value)*(document.Order.Price_D.value))
document.Order.totalE.value = dp((document.Order.Qty_E.value)*(document.Order.Price_E.value))
document.Order.totalF.value = dp((document.Order.Qty_F.value)*(document.Order.Price_F.value))
document.Order.totalG.value = dp((document.Order.Qty_G.value)*(document.Order.Price_G.value))
document.Order.totalH.value = dp((document.Order.Qty_H.value)*(document.Order.Price_H.value))
document.Order.Total_Value.value = dp(eval(document.Order.totalA.value) + eval(document.Order.totalB.value) + eval(document.Order.totalC.value) + eval(document.Order.totalD.value) + eval(document.Order.totalE.value) + eval(document.Order.totalF.value) + eval(document.Order.totalG.value) + eval(document.Order.totalH.value))
}
function regExp(ele)
{
d=ele.value.indexOf('.')
dot=/\./g
e=ele.value.substr(0,d+1)
if(d!=-1){e+=ele.value.substr(d+1, ele.value.length).replace(dot,'')}
re=/[^0-9.]+/g
ele.value=e.replace(re,'')
calculate()
}
</SCRIPT>

I use hidden fields for the line totals:

<input type="hidden" name="totalA">
<input type="hidden" name="totalB">
<input type="hidden" name="totalC">
<input type="hidden" name="totalD">
<input type="hidden" name="totalE">
<input type="hidden" name="totalF">
<input type="hidden" name="totalG">
<input type="hidden" name="totalH">

Here is what one of the lines looks like:

<TR>
<TD><p align="left"><FONT face="arial, helvetica" size=2>B)</FONT></p></TD>
<TD align=middle><p align="center"><INPUT size=12 name=Item_B></p></TD>
<TD align=middle><p align="center"><INPUT size=2 name=Qty_B onChange="calculate()"></p></TD>
<TD align=middle><p align="center"><INPUT size=18 name=Description_B></p></TD>
<TD align=middle><p align="center"><INPUT size=10 name=Price_B onChange="regExp(this)"><FONT face="arial, helvetica" size=2>EA.</FONT></p></TD>
</TR>