how do I write a code to search a website page for a specific word?

function searchAndHighlight(searchTerm, selector) {
    if(searchTerm) {
        //var wholeWordOnly = new RegExp("\\g"+searchTerm+"\\g","ig"); //matches whole word only
        //var anyCharacter = new RegExp("\\g["+searchTerm+"]\\g","ig"); //matches any word with any of search chars characters
        var selector = selector || "body";                             //use body as selector if none provided
        var searchTermRegEx = new RegExp(searchTerm,"ig");
        var matches = $(selector).text().match(searchTermRegEx);
        if(matches) {
            $('.highlighted').removeClass('highlighted');     //Remove old search highlights
                $(selector).html($(selector).html()
                    .replace(searchTermRegEx, ""+searchTerm+""));
            if($('.highlighted:first').length) {             //if match found, scroll to where the first one appears
                $(window).scrollTop($('.highlighted:first').position().top);
            }
            return true;
        }
    }
    return false;
}

$(document).ready(function() {
    $('#search-button').on("click",function() {
        if(!searchAndHighlight($('#search-term').val())) {
            alert("No results found");
        }
    });
});