Retrieving Data from a LookUp Column using ECMA Script

var myColl="";
var strCurrentWeb="";
var strCurrentSiteUrl="";
function BindLookUpData()
{
    try
    {
        var context = new SP.ClientContext.get_current();
        var web = context.get_web();
        strCurrentWeb=context.get_url();
        strCurrentSiteUrl=window.location.protocol + '//' + window.location.host + strCurrentWeb;
        var list = web.get_lists().getByTitle('Book Names');
        var sQuery="<View><Query><OrderBy><FieldRef Name='ID' /></OrderBy></Query></View>";
        var camlQuery = new SP.CamlQuery();
        camlQuery.set_viewXml(sQuery);
        this.myColl = list.getItems(camlQuery);
        context.load(this.myColl, 'Include(Title, ID, Category)');
        context.executeQueryAsync(Function.createDelegate(this, this.BindLookUpDataSuccess), Function.createDelegate(this, this.BindLookUpDataFailed));
    }
    catch(Ex)
    {
        alert(Ex);
    }
}

function BindLookUpDataSuccess()
{
    var strBookNames="";
    strBookNames+="<Table>";
    if(myColl.get_count()!=0)
    {
        var listEnumerator = this.myColl.getEnumerator();
        strBookNames+="<Tr>";
        strBookNames+="<Td Colspan='2' Align='Center' class='HeadingClass'>";
        strBookNames+="Retrieving Data from a Lookup column";
        strBookNames+="</Td>";
        strBookNames+="</Tr>";
        strBookNames+="<Tr>";
        strBookNames+="<Td class='HeadingClass'>";
        strBookNames+="Person Name";
        strBookNames+="</Td>";
        strBookNames+="<Td class='HeadingClass'>";
        strBookNames+="Category";
        strBookNames+="</Td>";
        strBookNames+="</Tr>";
        while (listEnumerator.moveNext())
        {
            var item = listEnumerator.get_current();
            var strItemID=item.get_item('ID');
            var strTitle=item.get_item('Title');
            var strCategory=item.get_item('Category').get_lookupValue();
            var strCategoryID=item.get_item('Category').get_lookupId();
            var strUrl=strCurrentSiteUrl+"Lists/Book Names/DispForm.aspx?ID="+strItemID+"&Source="+window.location.href;
            var strLookUpUrl=strCurrentSiteUrl+"Lists/Book Category/DispForm.aspx?ID="+strCategoryID+"&Source="+window.location.href;
            strBookNames+="<Tr>";
            strBookNames+="<Td class='LoopRecordsClass'>";
            strBookNames+="<A href='"+strUrl+"' class='LoopRecordsClass'>"+strTitle+"</a>";
            strBookNames+="</Td>";
            strBookNames+="<Td class='LoopRecordsClass'>";
            strBookNames+="<A href='"+strLookUpUrl+"'>"+strCategory+"</A>";
            strBookNames+="</Td>";
            strBookNames+="</Tr>";

        }
    }
    else
    {
        strBookNames+="<Tr>";
        strBookNames+="<Td Colspan='2' Align='Center' class='HeadingClass'>";
        strBookNames+="No Books Data Available";
        strBookNames+="</Td>";
        strBookNames+="</Tr>";

    }
   
   
    strBookNames+="</Table>";
    document.getElementById("tdBookNames").innerHTML=strBookNames;
}

function BindLookUpDataFailed(sender, args)
{
    alert('failed. Message:' + args.get_message());
}

function BindData()
{
    ExecuteOrDelayUntilScriptLoaded(BindLookUpData, "sp.js");
}

_spBodyOnLoadFunctionNames.push("BindData");