function validarTecla(id, evt) {
  var key;
  if(window.event)
    key = window.event.keyCode;     //IE
  else
    key = evt.which;     //firefox
  if(key == 13)
    $(id).submit();
}
function clearCombo(oCombo) {
	while(oCombo.options.length > 0) {
		oCombo.remove(0);
	}
}

function addOption(oCombo, value, text) {
	var oOption 	= document.createElement("OPTION");
	oOption.text	= text;
	oOption.value	= value;
	oCombo.options.add(oOption);
}

function comboGetSelectedText(oCombo) {
	for (i = 0; i < oCombo.options.length ; i++) {
		if (oCombo.options[i].selected) {
			return oCombo.options[i].text;
		}
	}
	return null;
}

function selectItemCombo(oCombo,sValue) {
  for (i = 0; i < oCombo.options.length ; i++) {
    if (oCombo.options[i].value == sValue) {
      oCombo.options[i].selected = true;
    }
  }
}

var show_request = function(i) {
  Effect.SlideDown('request-'+i);
};