/* SWAP (REPLACE) INDEX CONTENT BY THE CLICK OF A TAB */
function interAct(num){
	var tab = 'tab'+num;
	var aspect = $(tab).innerHTML;
	/* DISPLAY THE RELATED INFO & IMAGE */
	if (num == 1) {
		$('easier').show();
		$('anywhere').hide();
		$('faster').hide();
		$('smarter').hide();
	}
	if (num == 2) {
		$('faster').show();
		$('anywhere').hide();
		$('smarter').hide();
		$('easier').hide();
	}
	if (num == 3) {
		$('smarter').show();
		$('anywhere').hide();
		$('faster').hide();
		$('easier').hide();
	}
	if (num == 4) {
		$('anywhere').show();
		$('faster').hide();
		$('smarter').hide();
		$('easier').hide();
	}
	var four_tabs = ["tab1", "tab2", "tab3", "tab4"];
	var other_tabs = four_tabs.without(tab);
	/* UN-HIGHLIGHT THE HIGHLIGHTED TAB IN ORDER TO... */
	for (var i = 0, element; element = other_tabs[i]; i++) {
		var tab_num = element.substring(3);
		var tab_name = $(element).innerHTML;
		var new_name = tab_name.gsub('...', '');
		$(element).replace('<a href="javascript:;" id="'+element+'" onclick="interAct('+tab_num+')">'+new_name+'</a>');
	}
	/* $$('a.active').writeAttribute('class', ''); */
	/* ...MAKE THIS TAB THE ONLY HIGHLIGHTED TAB */
	$(tab).replace('<a href="javascript:;" id="'+tab+'" onclick="interAct('+num+')" class="active">...'+aspect+'</a>');
}