# Calculate a recurring payment and enter the number into a text field

Greetings,

On a credit card transaction form for donations I have a field for donation and a check box for "Break my donation into 12 payments".

So if this check box is checked I'd like to divide the donation by 12 and enter it into the totalcharge field. If it is not checked then the total amount they entered will go into the totalcharge field.

I have had some luck doing similar manipulation in the past with jquery but I am struggling a bit with this one.

Any suggestions will be greatly appreciated.

Thank you.

Sky
###### Who is Participating?

Commented:
You almost have it yourself.  A few minor corrections to your function:
``````function CalculateTotal() {
if ( document.donform.submode.checked ) {
document.donform.chargetotal.value=document.donform.donationtotal.value /12;
}
else {
document.donform.chargetotal.value = document.donform.donationtotal.value
}
}
``````

And, if you want to round your divided number to 2 decimal places, then replace the " = document.don.....value/12" with this:

`````` = Math.round(document.donform.donationtotal.value /12*100)/100
``````

Good luck
0

Commented:
can you put some of your code?
0

Author Commented:
I have a text field called "donationtotal" and a text field called "chargetotal"  and a check box called submode.

If submode is checked I want to divide donationtotal by 12 and make the result chargetotal. if it is not checked then donationtotal is copied to chargetotal.

0

Commented:
just write simple js function on change for Tickbox

function Tick12() {
var temp
temp=donationtotal

if submode == true {
temp=donationtotal /12
}
chargetotal = temp
}
0

Author Commented:
yes, this is what I am trying to do.
0

Author Commented:
Sorry i really don't know my syntax properly.

This is what I was writing in jquery:

<script>

\$('input[name=submode]').click(function(){
if(\$(this).is(':checked')){
\$('input[name=chargetotal]').val()= \$('input[name=donationtotal]').val()/12;
}
else{
\$('input[name=chargetotal]').val()= \$('input[name=donationtotal]').val();
}
});

});

</script>
0

Author Commented:
Ok,  This is my script in the head:

<script language="JavaScript" type="text/javascript">
<!--

function CalculateTotal() {

if document.donform.submode.value == true {
document.donform.chargetotal.value=document.donform.donationtotal.value /12
}
document.donform.chargetotal.value = document.donform.donationtotal.value
}

//-->
</script>

Then on the form field I have this:

<input name="donationtotal" type="text" size="15" onChange="CalculateTotal()" />

But nothing happens at all.

Thank you.
0
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