JavaScript - Variables in paths.

In form paths (ie. document.myForm.fieldOne.property()), is it possible to have a variable in it? So that when you send the data from a field, you can dynamically put the name into the path

Like:

onBlur="myFunction(this);"
-------------------------------------
function myFunction(field){
fieldName = field.name;
document.myForm.fieldName.select();
};

Thanks for any help you can give me

Dont worry. I worked it out.

I just needed to remove the 'document.myForm' bit and it worked.