Drag and release for rubber band box ...

I using Firefox mobile on a Nokia N900 (latest version 1.1) and I am trying to access a mapping site that supports the use of a rubber-band-box to define an area on the map into which you want to zoom. On the desktop you place your pointer at a corner of your desired area of interest, press the left mouse button, drag the pointer (the web site draws a box tracking your pointer) and then release to define the zoom region. My question is ... how do I do the same thing using mobile Firefox on the N900? The built-in microB browser "simulates" a mouse pointer and so works well but I have not been able to figure out how to do this with Firefox. Here is the web site that I am accessing: http://demo.cubewerx.com/demo/cubexplor/cubexplor.cgi == Extensions installed: == YouTube Enabler Near Me Yummy TwitterBar Hold4Tab