Is there an element of noscroll that will let you determine between vertical scrollbar and horizontal scrollbar?
You want to stop people from being able to navigate through your site why? If you mean other scrollbars on your page besides the two the browser makes at the sides, like if you have a box with overflow: auto on it, then whether the content fits width-wise or height-wise determines if there's a scrollbar that is horizontal or vertical. Know that your content may change size, so disabling scrollbars can be dangerous. Esp if grandma takes a look with the text enlarged by 200%. She can't scroll further to read the rest. If you're removing scrollbars for Javascripted boxes, use Javascript to remove the default scrollbars-- so those without javascript still have scrollbars, and those with javascript see exactly what you want them to.