Show Image in a Datalist

Dear *.*
I have a Datalist which have textbox control and an image control, the textbox value is the current stock of the item, here is my problem,how to change the image if the value of the textbox control is 0, the image url should be the "soldout.png" and if the texbox values is 1 or more, the image url should be "available.png"
Please help.....

thanks in advance...


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