function swap_tabindex(){
	var content = document.getElementById("conteneur_principal");
	if(content) {
		var index = 1;
		var champs = content.getElementsByTagName("a");
		for(var i=0, n=champs.length; i<n; i++) {
			if (champs[i].tabIndex == -1)
				champs[i].tabIndex = index;
			else
				champs[i].tabIndex = -1;
			index++;
		}
		
		var input = content.getElementsByTagName("input");
		for(var i=0, n=input.length; i<n; i++) {
			if (input[i].tabIndex == -1)
				input[i].tabIndex = index;
			else
				input[i].tabIndex = -1;
			index++;
		}
	}
}