Jessie, did you mean dtlDropdownWithDesc(I checked version 14.x and couldn't see there is a macro called dtlDropdownwithDescription)? if yes, take a look at the detail_forms.js file, where function detailDropdownWithDesc() is coded(this is the function got invoked by dtlDropdownWithDesc macro). Pay attention
to width:x%...this is where the length/width of the display. Thanks _Chi