Control Google Maps Zoom by your own html thru jQuery.

gistfile1.js

$('.control a').click( function() 
  {
		var currentZoom = map.getZoom();

		if( $(this).text() == '+') 
		{
			if( currentZoom < 4 )
			{
				var currentZoom = parseFloat( currentZoom ) + 1;
			}
		} 
		else
		{
			if( currentZoom > 2 )
			{
				var currentZoom = parseFloat( currentZoom ) - 1;
			}
		}

  		map.setZoom( currentZoom );
	});