for (i=0; i<document.getElementsByTagName("*").length; i++) {
    if (document.getElementsByTagName("*").item(i).className == "selectrecherche"){
      if( navigator.userAgent.toLowerCase().indexOf('msie 6') != -1 ) {
        document.getElementsByTagName("*").item(i).style.marginLeft="6px";
      }
      else {
        document.getElementsByTagName("*").item(i).style.marginLeft="8px";
      }
     }
  }