// Função usada para "encodar" urls
function url_encode( str ) {
	var encoded = "" ;
	var valid_uri_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789$-_.+!*'()," ;
	var hex_chars = "0123456789ABCDEF" ;
	for ( var i = 0 ; i < str.length ; i++ ) {
		if ( valid_uri_chars.indexOf( str.charAt( i ) ) == -1 ){
			encoded += "%" + hex_chars.charAt( str.charCodeAt( i ) >> 4 ) + hex_chars.charAt( str.charCodeAt( i ) & 0xF ) ;
		}
		else{
			encoded += str.charAt( i ) ;
		}
	}
	return encoded ;
}

// Função genérica para navegação que utilize tabs
function show_tab( obj_id ){
	if ( !document.getElementById ){
		return ;
	}
	var i , obj , parent_node ;
	if ( document.getElementById( obj_id ) ){
		obj = document.getElementById( obj_id ) ;
		obj_list = obj.parentNode.getElementsByTagName( obj.tagName ) ;
		for ( i = 0 ; i < obj_list.length ; i++ ){
			obj_list.item(i).style.display = "none" ;
		}
		obj.style.display = "block" ;
	}
}