function Concorrer( IDvaga) {
	var IDcandidato = $('IDcandidato').value;
	if ( IDcandidato <= 0 ) {
		document.location = './';
		return true;
	}
	
	var xhReq = createXMLHttpRequest();
	if ( xhReq == null ) { return false; }
	
	var targetDoc = "./ws.asp?OP=C"
			+ "&ID=" + IDcandidato 
			+ "&VAGA=" + IDvaga
			+ "&UID=" + generateUniqueID();
			
	xhReq.open( "HEAD", targetDoc, true);
	xhReq.onreadystatechange = function() {
		if ( xhReq.readyState != 4 ) { return; }
		var header_glcon_state = xhReq.getResponseHeader( 'glcon_state' );
		var header_glstatus = xhReq.getResponseHeader( 'glstatus' );
		var header_glmsg = xhReq.getResponseHeader( 'glmsg' );
		xhReq.close;
		xhReq = null;
		alert( header_glmsg.replace( /<br\/>/g, "\n" ) );
		if ( header_glstatus == 0 ) {
			document.location = document.location;
		}
	}
	xhReq.send( null );
	return true; 	
}