// -------- Header Dominio --------
var header_dominio = "www.terra.com.ve";
var dominio_tail="com.ve";

function _buscar(f) {
 f.action="http://buscador.terra." + dominio_tail + "/default.asp";
 if ((f.query.value.length == 0) || (f.query.value == "Buscar en Internet")) { alert('Ingrese el texto que desea buscar.'); f.query.focus(); return false; }
 else return true;
}

// -------- Header Contenido --------
var header_cont = '' +
'<style type="text/css">.combo { font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-weight: normal; color: 463D3E; text-decoration: none; border: 1px solid #999999; height: 18px; width: 152px;}</style>' +
'<form name="form_buscar" action="http://buscador.terra.' + dominio_tail + '/default.asp" method="get" onsubmit="return _buscar(this)">' +
'  <table border="0" align="right" cellpadding="0" cellspacing="1">' +
'    <tr>' +
'      <td width="152" height="28">' +
'        <div align="right">' +
'          <input name="query" type="text" class="combo" id="buscar" value="Buscar en Internet" size="30">' +
'        </div>' +
'                       </td>' +
'      <td width="94"><input name="buscador" type="image" src="http://' + header_dominio + '/img/bot_google.gif" width="94" height="28" border="0"></td>' +
'      <td width="32">&nbsp;</td>' +
'    </tr>' +
'  </table>';
'</form>';

document.write(header_cont);