Value Change from Several Input Text Boxes

[sandra45]

Hi, I want to change value of one input text box based on values changed from several input text boxes, can this be done? Let's say box A=8, if box B is changed to 1, value in box A=(8-1=7), and if box C is changed to 2, value in box A=(7-2=5) and so on.

Can anyone tell me how to do this? Thanks.

Regards,
Sandra

 

[vongrunt]

This is one possibility:

<form>
A:<input type="text" name="A" value="8"><br>
B:<input type="text" name="B" value="0" onchange="setA(this)"><br>
C:<input type="text" name="C" value="0" onchange="setA(this)"><br>
</form>

<script language="javascript">
function setA( oFld )
{	oForm = oFld.form;
	oForm["A"].value = parseInt(oForm["A"].value) - parseInt(oFld.value);
}
</script>

... and another one:

<form>
A:<input type="text" name="A" value="8"><br>
B:<input type="text" name="B" value="0"><br>
C:<input type="text" name="C" value="0"><br>
<input type="button" value="Change" onclick="setA( this.form )">
</form>

<script language="javascript">
function setA( oForm )
{	var B = parseInt( oForm["B"].value);
	var C = parseInt( oForm["C"].value);

	oForm["A"].value = parseInt(oForm["A"].value) - B - C;
}
</script>

 

[sandra45]

Hi, thanks a lot, it works great!!!