change the style of a gui by a key press

i am creating an inventory script that i want the user to press the numbers keys to interact with the bar along the bottom, but i cant get the images to change on key press only when they are clicked. i have tried using the toolbar but i get back errors, if someone knows a way in which to set a the toggle to active that would really help.

thanks in advance

function OnGUI() { var curIndex = 0; GUI.skin = customSkin; GUI.BeginGroup (new Rect (400, 500, 400, 120));

     for(var item : System.Collections.Generic.KeyValuePair.<String, GameObject> in items) {
         //iterate through all the items in the dictionary.
          var rect : Rect = new Rect((width+2) * curIndex, 0, width, buttonHeight);
          var customStyle : GUIStyle;
          var btnToggled : boolean;
          var itemIndex : int;
          itemIndex = curIndex;
          customStyle = "icon_"+item.Key;
          GUI.skin = customSkin;
          btnToggled = GUI.Toggle(rect, btnToggled, curIndex+1+")", customStyle);
          //Create a rect for the button.  It is offset more for each item in the array.
          if(Event.current.Equals (Event.KeyboardEvent (curIndex+1+""))) {
                curItem = item;
               //if the user clicks the button, select it as the current item.
          }
          if (curItem.Key == item.Key){
          btnToggled = true;
          }else{
          
          }
          curIndex++;
          //increase the offset counter.
     }

     GUI.EndGroup();

}