highlight a 'part' part of a given string ('highlight_string')

gistfile1.js

		function hightlight(highlight_string, part){
			workstring = highlight_string;
			var indices = [];
			var cut = all_cut = 0;
			while (workstring.indexOf(part) != -1) {
				index = workstring.indexOf(part);
				indices.push(index+all_cut);
				cut = index + part.length;
				workstring = workstring.substr(cut);
				all_cut = all_cut + cut;
			}
			var opentag = "<ins>";
			var closetag = "</ins>";
			for (var i in indices) {
				var offset = (opentag+closetag).length*i;
	 			highlight_string = highlight_string.substring(0, indices[i]+offset) + 
	 							opentag +
	 							highlight_string.substring(indices[i]+offset, indices[i]+part.length+offset) +
	 							closetag +
	 							highlight_string.substring(indices[i]+part.length+offset);
			}
			return highlight_string;
		}