Trouble resizing webplayer

I'm trying to resize my webplayer to fit a user's browser window. Here's my javascript in the html header:

     if (typeof unityObject != "undefined") 
 {
 //get the width of the window
 var winW;
 if (window.innerWidth)
 {
 winW = window.innerWidth;
 }
 else if (document.body && document.body.offsetWidth) //IE
 {
 winW = document.body.offsetWidth;
 }
 //set params
 var params = 
 {    
 backgroundcolor: "ffffff",
 bordercolor: "ffffff",
 textcolor: "000000",
 logoimage: "logo_webplayer.png",
 progressbarimage: "GUI_loading_filled.png",
 progressframeimage: "GUI_loading_empty.png"       
 };
 //embed the player
 unityObject.embedUnity("unityPlayer", "fit2cure.unity3d", 1060, 600, params);
 //get the player
 var unity = unityObject.getObjectById("unityPlayer");
 if (unity == null) {
 unity = document.getElementById("UnityObject");
 }
   if(unity == null) {
 unity = document.getElementById("UnityEmbed");
 }
 //set the width of the player
 if (unity != null) 
 {
 alert("not null");
 unity.style.width = winW;
 unity.style.height = 600 * winW / 1060;
 }
 else
 {
 alert("null");
 }
 }
 

Through alerts I've figured out that winW is getting the correct width and that despite trying to get the unityPlayer all different ways, it is still null when I try to set the width and height. What else should I try?