Need help with mouse over effect

Ok here is my idea, imagine you goto a page for t-shirt designs and there is a blank white t on the screen and a group of sample thumbnails below it. No if you want to see the sample on the t-shirt you "in-theory" mouse over it and the image will appear on the t-shirt. How do I do it? I can make a simple mouse over but not make one that shows the over image in a different spot of the page. Can anyone please help me?

 

This is pretty simple actually You need to do something like that:
You have an image that shows the big t-shirt, lets say it's code is this:

<img src='bigimage.jpg' id='bigimgage'>

Code (markup):

Then you have the thumbnails of the other t-shirts. Their event handler can be this:

<img src='other_pic_1.jpg' onmouseover='changePic(this.src)'>

Code (markup):

and the changePic() function:

function changePic(newImage)
{
  //all you do is access the bigimage element, which contains the blank t-shirt and change it's src property to point to the mouseovered one.
  document.getElementById('bigimage').src = newImage;
}

Code (markup):