function show_front_wheel()
	{
		var html = '<div class="group_button" id="left_button_frontwheel" onClick="hide_front_wheel();" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">Front Wheel</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_frontwheel-hub" onClick="request_group(7,15);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Hub</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_frontwheel-rim" onClick="request_group(10,16);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Rim</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_frontwheel-spokes" onClick="request_group(21,17);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Spokes</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_frontwheel-tire" onClick="request_group(16,18);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Tire</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_frontwheel-tube" onClick="request_group(22,19);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Tube</div>' ;
		document.getElementById('front_wheel_builder').innerHTML = html ;
		front_wheel_buttons_visible = true ;
		check_left_buttons();
	}
	
	function hide_front_wheel()
	{
		var html = '<div class="group_button" id="left_button_frontwheel" onClick="show_front_wheel();" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">Front Wheel</div>' ;
		document.getElementById('front_wheel_builder').innerHTML = html ;
		front_wheel_buttons_visible = false ;
		check_left_buttons();
	}
	
	function show_rear_wheel()
	{
		var html = '<div class="group_button" id="left_button_rearwheel" onClick="hide_rear_wheel();" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">Rear Wheel</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_rearwheel-hub" onClick="request_group(7,20);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Hub</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_rearwheel-rim" onClick="request_group(10,21);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Rim</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_rearwheel-spokes" onClick="request_group(21,22);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Spokes</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_rearwheel-tire" onClick="request_group(16,23);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Tire</div>' ;
		html = html + '<div class="sub_group_button" id="left_button_rearwheel-tube" onClick="request_group(22,24);" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">- Tube</div>' ;
		document.getElementById('rear_wheel_builder').innerHTML = html ;
		rear_wheel_buttons_visible = true ;
		check_left_buttons();
	}
	
	function hide_rear_wheel()
	{
		var html = '<div class="group_button" id="left_button_rearwheel" onClick="show_rear_wheel();" onMouseOver="left_button_mouse_over(this);" onMouseOut="left_button_mouse_out(this);">Rear Wheel</div>' ;
		document.getElementById('rear_wheel_builder').innerHTML = html ;
		rear_wheel_buttons_visible = false ;
		check_left_buttons();
	}