Resizing / Rescaling Image inside GUI.Window content.

I am trying to rescale an image within the content of a GUI.Window.

The code comes up with an error "Assets/TextAreaBox.js(14,43): BCE0051: Operator '*' cannot be used with a left hand side of type 'int' and a right hand side of type 'Object'.".

 #pragma strict
 
 private var BoxWidth = 350;
 private var BoxHeight = 400;
 
 var image_1 : Texture2D;
 private var maxImageWidth = BoxWidth-50;
 private var ImageRatio;
 private var NewImageWidth_1 = image_1.width;
 private var NewImageHeight_1 = image_1.height;
 if(image_1.width > maxImageWidth){
     ImageRatio = maxImageWidth / image_1.width;
     NewImageWidth_1 = image_1.width * ImageRatio;
     NewImageHeight_1 = image_1.height * ImageRatio;
 }