What does this mean?

I’ve got this code to open a new window when I press a button, and in the window it should display a .SWF:

on (release) {
getURL ("javascript:NewWindow=window.open('Gallery_Item_Template.swf','Gallery','width=401,height=304,left=0,top=0,toolbar=No,location=No,scrollbars=No,status=No,resizable=No,fullscreen=No');  NewWindow.focus();	  void(0);");

When I check the syntax it says it’s all ok, but when I preview it, the output window says this:

[size=1][color=DimGray]Error Scene=Scene 1, layer=Jar1, frame=1:Line 1: Wrong number of parameters; getURL requires between 1 and 3.

[size=2][color=Black]Whaaa? What’s wrong?[/color][/size]