javascript will not calculate and input my results back into my form

[User]

Trying to pull information from my form input fields and calculate them using Javascript. Its not quite working in my favor. \[quote\] HTML CODE on default1.html\[/quote\]\[code\] <script type="text/javascript" src="http://stackoverflow.com/questions/14061184/multiplication.js" language="javascript"></script> <form> <table> <tr><!--Row 2--> <td class="tdSize7"><input class="input" name="name1" type="text"/></td> <td class="tdSize7"><input class="input" name="source1" type="text"/></td> <td class="tdSize8"><p>$</p></td> <td class="tdSize9"><input class="input" name="income1" type="text"/></td> <td class="tdSize8"><p>X12</p></td> <td class="tdSize8"><p>$</p></td> <td class="tdSize9"><input name="ann1" disabled="disabled"/></td> </tr> <td class="tdSize9"><input class="inputSize2" name="" type="button" value="http://stackoverflow.com/questions/14061184/Calculate" onclick="addme(this.form)"/></td> </table> </form> \[/code\]\[quote\] JAVASCRIPT CODE on multiplication.js \[/quote\]\[code\] function addme(form){ //Constant Variables const twelve = Number (12); const fourHun = Number (400); const fourHunEighty = Number (480); //Monthly Income 1 var income1 = Number(frm.income1.value); var val = income1 * twelve; frm.ann1.value = http://stackoverflow.com/questions/14061184/val;}\[/code\]My javascript will not calculate and input my results back into my form.
This is just a sample of my code. i am hoping this will tell you enough and help you. In helping me in fixing my problem.