Problems with saveAs

I wonder whether anyone can help me with the following problem. I've been pulling my hair out for 3 days now.

Basically I have produced a script that places a button on the Reader 7 toolbar. When clicked I want the button to save the current document to a folder on my C drive. Sounds pretty easy? Not really.

I keep getting the error "TypeError: Invalid Argument Type" whenever the saveAs code is called.

I've listed my code below. The document I am using has save rights and the folder exists on my C drive.

Can anyone help???

PS - I am using the free version of acrobat reader downloaded from Adobe website.

// add a toolbutton
app.addToolButton({
cName: "myToolButton",
cExec: "trustedNewDoc()",
cTooltext: "Email or Fax Document",
cLabel: "Communicate"
});

trustedNewDoc = app.trustedFunction( function ()
{
// Additional code may appear above
app.beginPriv(); // Explicitly raise privilege
try {
app.alert("In function")
this.saveAs ("/C/DavidTemp/Me.pdf");
}
catch (err) {
app.alert("Error: " + err);
}
app.endPriv();
// Additional code may appear below.
})