How to pass textbox name to function in javascript

[Len Elyea]

I have a php script which dynamically creates a table containing text boxes with variable names.

echo '<td align="center" bgcolor="'.$bgcolor.'"><input type="text" name="payable_'.$key.'" id="payable_'.$key.'" value="'.$payable.'" size="3" maxlength="4" /></td> ';

In the above instance the text box name might be 'payable_23323' .

I need to code an onKeyUp event which sends the text box name to a function, and in that function I need to retrieve the text box name and the string after 'payable_' together with the value the user has input into the text box.

Any help is greatly appreciated . . . I have been Googling this for hours to no avail - probably because I don't know what to search for . . .

Thanks

[Logic Ali]

<input ... onkeyup = "myFunction( this )">

...

function myFunction( elem )
{
 alert( elem.name.substring( elem.name.lastIndexOf( '_' ) + 1 ) + '\n\n' + elem.value );
}