Setting the background color of an <li> element in a body onLoadJavascript function

[Edward Diener]

I have a body onLoad Javascript function which is being called and I
want to set the background color of an <li> element in my document which
has a unique id. I have tried various incantations such as:

document.getElementById('myLIelementID').style.bgcolor = "red";

all to no effect. Does anybody know the precise code in Javascript to
get this done ?