function setActiveMenu(menuItem)
	//Function:		Set active menu item in side menu or in top menu.
	//Parameters:   menuItem	- Identify menu item which is to be set active:menu# or tab#.
	//Author:		Endeavour
	//Modified:		29-Dec-2006	- First release
	//Notes:		-
	//Suggestions: 	-
	{
	var id;
	var element;
	var menuItem;

	//Determine which menu (side or top) is to be switched on.
	if (menuItem.substring(0,3) == 'tab')
	{	//Switch on the active tab in the topbar menu (in the "Contents" frame, i.e. this frame).
		id = 'activetab';
		top.Contents.document.getElementById(id).className = menuItem;

		//Switch off the active tab in the sidebar menu (in the "Sidebar" frame).
		top.Sidebar.document.getElementById('activemenu').className = 'none';

//D		window.alert('Function setActiveMenu:' +
//D			'\nSwitch on menu item in topbar: ' + document.getElementById(id).className +
//D			'\nSwitch off active menu in sidebar' )
	}
	else
	{	if (menuItem.substring(0,4) == 'menu')
		{	//Switch on the selected menu item in the sidebar frame.
			id = 'activemenu';
			top.Sidebar.document.getElementById(id).className = menuItem;
			
			//The active menu in the topbar is automatically switched off by loading a content page
			//originating from the side bar menu

//D			window.alert('Function setActiveMenu:' +
//D				'\nSwitch on menu item in sidebar: ' + top.Sidebar.document.getElementById(id).className +
//D				'\nActive menu in topbar is automatically switched off' )

		}
		else
		{
//D			window.alert('Function setActiveMenu:' +
//D				'\nIllegal function argument' )

			return false;
		}
	}
	}