Passing values

Passing values

Have a pretty basic question (I think).

I'm trying to integrate a jquery plugin into a client site. The plugin is initiated with a call like this:
jQuery('#services-example-1').services(
{ 
width:920,
height:295, 
callBack:function() {}
});




I do not want the width value to be hard coded, but want to detect the width of the enclosing div with code something like this:
var colwidth = $('#divname').width();
and pass the value for colwidth in place of the constant "920". I have tried a few things, but none have so far resulted in the value getting inserted, only the code I have tried.

Any suggestions?

Thanks.