Change width of text entry box in a Multiple chocie answer with text entry

Hi all,
I'm using the below Javascript code to move the text entry box to the right of the answer box, but I also want to change the width. Changing the width in % or px in the code doesn't seem to change the actual width of the entry boxes. Also, if I choose the larger entry box options for the type of text entry boxes, the whole thing breaks down and the box is put underneath.
Qualtrics.SurveyEngine.addOnReady(function()
{
    jQuery("#"+this.questionId+" .TextEntryBox").each(function() {
      var tb = jQuery(this);
      tb.css({"float":"none","background-color":"white","width":"100px"});
      tb.prev("label").css("display","block").append(" ").append(tb);
  });

});
This produces:
But I want the entry box to be about 3-4 times wider.

Any help would be appreciated. Thanks!