Email conversation
| From | James Polanski |
|---|
| To | Me |
|---|
| Subject | Code Problems |
|---|
| Date | 20 July 2003 06:32 |
|---|
I am trying to do a simple calculation in Javascript. The following is the
code, and it is not working. Can you offer any help?
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Transmitter O</title>
<script LANGUAGE="JavaScript">
function neterp(transmitter, antenna, erp, form) {
//need to multiply the Inverse Log of antenna * .1 to get ratio
ratio = (Math.log(antenna) / Math.log(10))*.1;
form.erp.value = ratio * transmitter;
}
</script>
</head>
<body>
<form>
<div align="center"><center><table width="489">
<tr>
<td align="right" width="263" valign="middle">Transmitter O/P =</td>
<td align="left" width="218" valign="middle"><input type="text" size="8" value
name="transmitter"> watts</td>
</tr>
<tr>
<td align="right" width="263" valign="middle">Antenna Gain (after line loss) = </td>
<td align="left" width="218" valign="middle"><input type="text" size="8" value
name="antenna"> dBd</td>
</tr>
<tr>
<td width="481" align="center" valign="middle" colspan="2"><input type="button"
value="Calculate ERP" onClick="neterp(this.form.erp);"></td>
</tr>
<tr>
<td width="481" align="center" valign="middle" colspan="2"><input type="text" name="erp"
size="9"> Watts</td>
</tr>
</table>
</center></div>
</form>
</body>
</html>
| From | Me |
|---|
| To | James Polanski |
|---|
| Subject | Re: Code Problems |
|---|
| Date | 21 July 2003 08:50 |
|---|
James,
Your button onclick handler only passes one variable to the function, but
your function expects four. Try
---
onclick="neterp(this.form.transmitter.value,this.form.antenna.value,'unused',this.form);"
---
or, even more easy, use
---
onclick="neterp(this.form);"
function neterp(form) {
ratio = (Math.log(form.antenna.value) / Math.log(10))*.1;
form.erp.value = ratio * form.transmitter.value;
}
---
or, even more easy again, use
---
onclick="this.form.erp.value=(Math.log(this.form.antenna.value)/Math.log(10))*0.1*this.form.transmitter.value;"
---
Hope this helps
Tarquin
| From | James Polanski |
|---|
| To | Me |
|---|
| Subject | Re: Code Problems |
|---|
| Date | 21 July 2003 23:18 |
|---|
Tarquin:
I appreciate your help enormously....just your few lines of code turned a
light bulb on in my head and enabled me to better understand the handler
process.
Much appreciated.
I'm a JavaScript beginner......and have completed the page I was working on.
If you like, you can view it at:
http://xxx.xxxxxxxxxxxx.xx/calculators.html
James