function showhide(toShow){

var menu1, menu2, visu1, visu2;

if( document.getElementById ){ // this is the way the standards work
	menu1 = document.getElementById( 'submenu-1' );
	menu2 = document.getElementById( 'submenu-2' );
}else if( document.all ){ // this is the way old msie versions work
	menu1 = document.all['submenu-1'];
	menu2 = document.all['submenu-2'];
}else if( document.layers ){ // this is the way nn4 works
	menu1 = document.layers['submenu-1'];
	menu2 = document.layers['submenu-2'];
}
	
if(toShow == 1){
	menu1.style.display = 'block';
	menu2.style.display = 'none';
	document.getElementById('lagence').className += " up";
	document.getElementById('prestas').className = "cat-item";
}

if(toShow == 2){
	menu1.style.display = 'none';
	menu2.style.display = 'block';
	document.getElementById('prestas').className += " up";
	document.getElementById('lagence').className = "cat-item";
}

}

function hideall(){
	document.getElementById( 'submenu-1' ).style.display = 'none';
	document.getElementById( 'submenu-2' ).style.display = 'none';
	document.getElementById('lagence').className = "cat-item";
	document.getElementById('prestas').className = "cat-item";
}

//creer une autre fonction isOn() pour savoir quelle tete de menu est hilightée
// OU changer le lien en onmouseover