var originalLeftBackgroundImageUrl = null;
var originalLeftBackgroundColor = null;

function SetLeftBackgroundImage(productName) 
{
    var leftDiv = document.getElementById("Left");
    if (originalLeftBackgroundImageUrl == null) 
    {
        originalLeftBackgroundImageUrl = leftDiv.style.backgroundImage;
    }
    if (originalLeftBackgroundColor == null) 
    {
        originalLeftBackgroundColor = leftDiv.style.backgroundColor;
    }    
    leftDiv.style.backgroundImage = "url(/ProductImages/" + productName + ".jpg)";
    leftDiv.style.backgroundColor = "#FFF";
}

function RestoreLeftBackgroundImage() 
{
    var leftDiv = document.getElementById("Left");
    leftDiv.style.backgroundImage = originalLeftBackgroundImageUrl;
    leftDiv.style.backgroundColor = originalLeftBackgroundColor;
}