Passing function parameters from an XML doc

Hi-

I’m having an issue with calling a function from an imported XML file. This is my function:

function SwitchImage(movieName) {
this.popBox.popImage.loadMovie(movieName);
this.popBox.popCaption = “Go Bulldogs”;
}

This is the XML. The function works fine. It calls the function “SwitchImage” and it loads the image “1.jpg”.

<myLife >
<pagetext whatYear=“1959”>I was born on February 4<a href=“asfunction:_global.shell.SwitchImage,images/1.jpg”>change picture</a></pagetext>
</myLife>

Now I want to pass it another parameter called “popCaption”:

function SwitchImage(movieName, popCaption) {
this.popBox.popImage.loadMovie(movieName);
this.popBox.popCaption = (popCaption);
}

<myLife >
<pagetext whatYear=“1959”>I was born on February 4<a href=“asfunction:_global.shell.SwitchImage,images/1.jpg, my new caption”>change picture</a></pagetext>
</myLife>

I’m not sure what I’m doing wrong, but it must be in the XML. Any help is appreciated.
Thanks,
Clemente