function showFrame(name, bShow)
{
    var frameobj = document.getElementById(name+'_frame');
    
	var display = (bShow ? '' : 'none');
    
	if(display != frameobj.style.display) { 
		frameobj.style.display = display;
	}

}

function setLayout(id)
{
	//0 = left + main + right
	//1 = left + main
	//2 = main

	var objLeftFrame  = document.getElementById('left_frame'); // 216px
	var objMainFrame  = document.getElementById('main_frame'); // 334px
	var objRightFrame = document.getElementById('right_frame'); // 200px

	var objiLeftFrame  = document.getElementById('iframe_left'); // 216px
	var objiMainFrame  = document.getElementById('iframe_main'); // 334px
	var objiRightFrame = document.getElementById('iframe_right'); // 200px
	
	switch (id) {
		case 0:	
				// use for older browsers (below 5.5)
				objLeftFrame.style.width = '215px';
				objMainFrame.style.width = '334px';
				objRightFrame.style.width = '200px';
				
				// regular use for setting the layout
				objiLeftFrame.style.width = '215px';
				objiMainFrame.style.width = '334px';
				objiRightFrame.style.width = '200px';
		
				showFrame('left',true);
				showFrame('right',true);

				
				break;
		case 1:	// use for older browsers (below 5.5)
				objLeftFrame.style.width = '215px';
				objMainFrame.style.width = '535px';
				objRightFrame.style.width = '0px';

				// regular use for setting the layout
				objiLeftFrame.style.width = '215px';
				objiMainFrame.style.width = '535px';
				objiRightFrame.style.width = '0px';

				showFrame('left',true);
				showFrame('right',false);

				break;

		case 2:	// use for older browsers (below 5.5)

				objLeftFrame.style.width = '0px';
				objMainFrame.style.width = '750px';
				objRightFrame.style.width = '0px';
				
				// regular use for setting the layout
				objiLeftFrame.style.width = '0px';
				objiMainFrame.style.width = '750px';
				objiRightFrame.style.width = '0px';

				/* BEGIN *
				/ 
				/ IE Drawing bug protector :)
				/
				/ IE geeft een drawing fout als de frameset wordt uitgezet. Helaas
				/ is dit voor browsers zoals Opera nou juist wel weer belangrijk.
				/
				*/
		
				if ( navigator.userAgent.indexOf("Opera")!= -1 ) {
					showFrame('left',false);
					showFrame('right',false);
				}

				/* END */
				
				break;
	}
}

function loadFrame(name, url)
{
	var frameobj = document.getElementById('iframe_'+name);
    frameobj.src = url;
}

var _active_tab;

function showTab(name)
{
	//reset active tab to blue
	if(_active_tab){		
		obj = document.getElementById('tab_'+_active_tab);
		obj.style.backgroundImage = "url('images/tab_blue.gif')";
	}
	if(!name) {
		//set new tab to active 
		obj = document.getElementById('tab_'+_active_tab);
		obj.style.backgroundImage = "url('images/tab_blue.gif')";
	} else {
		//set new tab to active 
		obj = document.getElementById('tab_'+name);
		obj.style.backgroundImage = "url('images/tab_white.gif')";
		_active_tab = name;
	}
}