function criaRequisicao( obj ){

	if( window.XMLHttpRequest ) obj.req = new XMLHttpRequest();
	else if( window.ActiveXObject ) obj.req = new ActiveXObject( "Microsoft.XMLHTTP" ); 

}

function mandaRequisicaoGET( obj, url, sync, callback ){

	if( obj.req ){
		obj.req.onreadystatechange = eval( callback );
		obj.req.open( "GET", url, sync );
		obj.req.send( null );			
	}

}

function mandaRequisicaoPOST( obj, url, fields, sync, callback ){

	if( obj.req ){
		obj.req.onreadystatechange = eval( callback );
		obj.req.open( "POST", url, sync );
		obj.req.setRequestHeader( "Content-type", "application/x-www-form-urlencoded" );
		obj.req.setRequestHeader( "Content-length", fields.length );
		obj.req.setRequestHeader( "Connection", "close" );
		obj.req.send( fields );
	}

}

function destroiRequisicao( obj ){
	
	obj.req = null;
	obj = null;
	
}

function urldecode( txt ){

	return unescape( txt.replace(/\+/g," ") );

}