function ViewPage(myPageNumber){
		document.getElementById("page_home").style.display = 'none';
		document.getElementById("page_training").style.display = 'none';
		document.getElementById("page_customers").style.display = 'none';
		document.getElementById("page_contact").style.display = 'none';

		for(cptMenu = 1; cptMenu <= 4; cptMenu++){
			document.getElementById("menu_" + cptMenu).style.background = 'white';
			document.getElementById("menu_" + cptMenu).style.color = 'black';
		}

		document.getElementById("menu_" + myPageNumber).style.background = 'gray';
		document.getElementById("menu_" + myPageNumber).style.color = 'white';
		
		switch(myPageNumber){
			case 1:
				document.getElementById("page_home").style.display = '';
				break;
			case 2:
				document.getElementById("page_training").style.display = '';
				break;
			case 3:
				document.getElementById("page_customers").style.display = '';
				break;
			case 4:
				document.getElementById("page_contact").style.display = '';
				break;
		}
	}
	
	function ViewContactPage(){
		ViewPage(3);
		document.getElementById('mailFrame').src= 'mailto:' + 'anne.deneck' + '@' + 'skynet' + '.be';
	}