WebTextEdit ClientSideEvent Javascript-Can't Eval

Hi, I urgently need help, please not sure of correct forum.

WebtextEdit ClientSideEvent execute javascript statement on mousemove event. I can successfully change the style of another object type on this WebTextEdit ClientSide MouseMove event:document.getElementById("Object2").style.backgroundColor = '#F0F5F7';

But when I want to change the style of the WebTextEdit control:
document.getElementById("WebTextEdit1").style.backgroundColor = '#F0F5F7'; Then nothing happens

When I execute the script on the same WebTextEdit Clientside for another object which is not a WebtextEdit:
Object2.style.border='1px solid #FFE6A0'; Then it works

But when I want to change the WebtextEdit Clientside style:
WebTextEdit1.style.border='1px solid #FFE6A0';

Then I get Error: Can't Eval WebTextEdit1.style.border='1px solid #FFE6A0';

Please Help