function hide_all() {
	var myDiv = document.getElementById('introductionDiv');
    myDiv.style.display = "none";
	
	var myDiv = document.getElementById('detailsDiv');
    myDiv.style.display = "none";

    var myDiv = document.getElementById('creditsDiv');
    myDiv.style.display = "none";
}

function show_hide(theDiv){
	 hide_all();
     var myDiv = document.getElementById(theDiv);
	 myDiv.style.display = "block";
}