extracting parameter in function

[rav3]

Hi,
Is it possible to extract the arguement in function to use it as a string?
For example
function LoadImage(category:String){
this."category"_mc.onRollOver = function(){
};
}

Thanks in advanced,
rav3

[rabidGadfly]

function LoadImage(category:String){
this[category+"_mc"].onRollOver = function(){
};
}