struth, cobber. you really made a dog's breakfast out of that one
- document.getElementById should refer to the id of the element you are trying to manipulate, in this case the image, not the link.
- you don't need to add image.style - just access it's style attribute directly (unless you had something else in mind)
- be careful with setting things to percentages - 125% of what, exactly?
<a href="" onmouseover="html5_hover()" >
<img id="html5_position" src="Images/HTML5_Logo.jpg" alt="HTML5 logo" />