function highlight(text,keyword) {
    var chapter = text;
    if (navigator.appVersion.indexOf("Mac")!=-1) {
      var strHighlight = chapter;  
    }else { 
	var strfront = '<span style="background-color: yellow;">';   
    var strback = '</span>';
	var myString = keyword
	var myString = myString.replace(/and /gi, "");
	var myString = myString.replace(/or /gi, "");
	var myString = myString.replace(/not /gi, "");
	keywords = new Array()
	keywords=myString.split(" ")
	  for (i = 0; i < keywords.length; i++) {
		  var rg = "/" + keywords[i] + "/gi";
	      var chapter = chapter.replace(eval(rg), strfront + "$&" + strback);
	  }
   }
    return(chapter);
}