function is_email(str)
{
	var filtro = /^[A-Za-z][A-Za-z0-9_.-]*@[A-Za-z0-9_.-]+\.[A-Za-z0-9_.]+[A-za-z]$/;
	if (filtro.test(str)) return true;
	else return false;
}
function is_date(date_string)
{
	// matches DD/MM/Y or DD/MM/YYYY or D/M/Y or DD/M/YYYY Leap years treated.
	reg_expr = /^(((0?[1-9]|[12]\d|3[01])[\.\-\/](0?[13578]|1[02])[\.\-\/]((1[6-9]|[2-9]\d)?\d{2}|\d))|((0?[1-9]|[12]\d|30)[\.\-\/](0?[13456789]|1[012])[\.\-\/]((1[6-9]|[2-9]\d)?\d{2}|\d))|((0?[1-9]|1\d|2[0-8])[\.\-\/]0?2[\.\-\/]((1[6-9]|[2-9]\d)?\d{2}|\d))|(29[\.\-\/]0?2[\.\-\/]((1[6-9]|[2-9]\d)?(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00)|00|[048])))$/;
	if (!reg_expr.test(date_string)) {
		return false;
	}
	return true;
}
function popup_locked(url, w, h)
{
	win = window.open(url, '', 'width='+w+',height='+h+',toolbar=no,menubar=no,scrollbars=yes,resizable=no');
	win.moveTo(window.screen.availWidth / 2 - w / 2, window.screen.availHeight / 2 - h / 2);
}

function text_optimize(str)
{
	// replace with unicode characters:
	str = str.replace('á', '\u00E1');
	str = str.replace('é', '\u00E9');
	str = str.replace('í', '\u00ED');
	str = str.replace('ó', '\u00F3');
	str = str.replace('ú', '\u00FA');
	return str;
}
function urlencode(str)
{
    var result = "";
    for (i = 0; i < str.length; i++) {
        if (str.charAt(i) == " ") result += "+";
        else result += str.charAt(i);
    }
    return escape(result);
}

/**************** Efectos Inputbox ****************/
// Borrar el texto del input box.
function text_focus(id_input, default_text)
{
	if ($F(id_input) == default_text) {
		$(id_input).value = '';
	}
}
// Devolver texto original del input box.
function text_blur(input_text, text)
{
	if (input_text.value == '') input_text.value = text;
}
/**************** Fin Efectos Inputbox ****************/

String.prototype.trim = function() {
  return this.replace(/^\s+/, '').replace(/\s+$/, '');
};