Image resize proportional to window resize

Image resize proportional to window resize

i need to resize an inline img upon user window resize, while respecting the original proportions from image/window... using the following code, the image gets resized way too much... what am i doing wrong? must be some logic mistake by me... please help 
  1.     
    
     $
     (
     window
     ).
     resize
     (
     function
     () 
     {
    
    
    
    
     
    
    
    
    
    
             
     // window dimenstions
    
    
    
     
     var 
     windowWidth 
     = 
     $
     (
     window
     ).
     width
     ();
    
    
    
     
     var 
     windowHeight 
     = 
     $
     (
     window
     ).
     height
     ();
    
    
    
    
     
    
    
    
    
    
             
     // figure dimensions
    
    
    
    
             
     var 
     figureWidth 
     = 
     $
     (
     '#detailScreen figure'
     ).
     width
     ();
    
    
    
    
             
     var 
     figureHeight 
     = 
     $
     (
     '#detailScreen figure'
     ).
     height
     ();
    
    
    
    
     
    
    
    
    
    
             
     // proportions figure/window
    
    
    
    
             
     var 
     widthPropWinToBigImg 
     = 
     figureWidth 
     / 
     windowWidth
     ;
    
    
    
    
             
     var 
     heightPropWinToBigImg 
     = 
     figureHeight 
     / 
     windowHeight
     ;
    
    
    
    
     
    
    
    
    
    
             
     // resize figure according to proportion
    
    
    
    
             
     $
     (
     '#detailScreen figure'
     ).
     css
     ({
    
    
    
    
                 
     'width'
     : 
     figureWidth 
     * 
     widthPropWinToBigImg
     ,
    
    
    
    
                 
     'height'
     : 
     figureHeight 
     * 
     heightPropWinToBigImg
     ,
    
    
    
    
             
     })
    
    
    
    
     });