function abre(arquivo){
			var xmlHttp;
			try {
				// Firefox, Opera 8.0+, Safari
				xmlHttp=new XMLHttpRequest();
			}
			catch (e) {
				// Internet Explorer
				try {
					xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
				}
				catch (e){
					try {
						xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
					} 
					catch (e) {
						alert("Seu navegador não suporta AJAX.");
						return false;
					}
				}
			}
		    xmlHttp.onreadystatechange=function() {
				if(xmlHttp.readyState == 1) {
					document.getElementById("div_palestras").innerHTML = "<center>Carregando...<p>&nbsp;</p><object classid='clsid:D27CDB6E-AE6D-11cf-96B8-444553540000' codebase='http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,28,0' width='42' height='42'><param name='movie' value='img/carregando.swf' /><param name='quality' value='high' /><param name='wmode' value='transparent' />					<embed src='img/carregando.swf' width='42' height='42' quality='high' pluginspage='http://www.adobe.com/shockwave/download/download.cgi?P1_Prod_Version=ShockwaveFlash' type='application/x-shockwave-flash' wmode='transparent'></embed></object>";

				}
				if(xmlHttp.readyState == 4) {
					document.getElementById("div_palestras").innerHTML = xmlHttp.responseText;

				}
		    }
		    xmlHttp.open("GET",arquivo,true);
		    xmlHttp.send(null);
		}