jordan says:
        clsProductPearlMain objpp = new clsProductPearlMain(true);
        
        
        objpp.getCatPro();
        string str = string.Empty;
        
        int j = 0;
         
         
            for (j = 0; j < objpp.ListclsProductPearlMain.Count; j++)
            {
               
                    
                    if (File.Exists(Server.MapPath("images/ProductPearl/" + objpp.ListclsProductPearlMain[j].ProductID + ".jpg")))
                    {
                        str += @"<div class='row col-md-3 col-xs-6 hovereffect'>
                        <div class='imageBackGround' style='width:250px;height:280px;'>
                        <img class='imges'  style='height:220px;' src='images/ProductPearl/" + objpp.ListclsProductPearlMain[j].ProductID + ".jpg" + @"' />
                            <p class='sname'>" + objpp.ListclsProductPearlMain[j].ProductName + @"</p>
                        <p class='sname2'>" + objpp.ListclsProductPearlMain[j].MRP + @"</p></div><br/>
        </div>";
                    }
                    
                }
          
             
        
         
        product.InnerHtml = str;
 Place above code in different method and call that method in pageload event like below
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        BindImagesOnPageStart();
    }
}
public void BindImagesOnPageStart()
{
    clsProductPearlMain objpp = new clsProductPearlMain(true);
    //   objProduct.getProduct();
    objpp.getCatPro();
    string str = string.Empty;
    int j = 0;
    for (j = 0; j < objpp.ListclsProductPearlMain.Count; j++)
    {
        // string path = objProduct.ListclsProductMain[i].ProductID+".jpg";
        if (File.Exists(Server.MapPath("images/ProductPearl/" + objpp.ListclsProductPearlMain[j].ProductID + ".jpg")))
        {
            str += @"<div class='row col-md-3 col-xs-6 hovereffect'>
                    <div class='imageBackGround' style='width:250px;height:280px;'>
                    <img class='imges'  style='height:220px;' src='images/ProductPearl/" + objpp.ListclsProductPearlMain[j].ProductID + ".jpg" + @"' />
                        <p class='sname'>" + objpp.ListclsProductPearlMain[j].ProductName + @"</p>
                    <p class='sname2'>" + objpp.ListclsProductPearlMain[j].MRP + @"</p></div><br/>
    </div>";
        }
    }
    //}
    product.InnerHtml = str;
}
 
jordan says:
<script type="text/javascript">
       $(function () {
           $('#menu ul li a').click(function () {
               var selectedLink = $(this)[0].innerHTML
               localStorage.setItem('selectedLink', selectedLink);
           });
       });
       window.onload = function () {
           $('#menu ul li a').each(function () {
               if ($(this)[0].innerHTML == localStorage.getItem('selectedLink')) {
                   $(this).attr('style', 'background-color:deeppink');
                   localStorage.removeItem('selectedLink');
               }
               else {
                   $(this).attr('style', 'background-color:none');
               }
           });
       }
   </script>
 replace above script with below
<script type="text/javascript">
    $(function () {
        $('#menu ul li a').click(function () {
            var selectedLink = $(this)[0].innerHTML
            localStorage.setItem('selectedLink', selectedLink);
        });
    });
    window.onload = function () {
        $('#menu ul li a').each(function () {
            if ($(this)[0].innerHTML == localStorage.getItem('selectedLink')) {
                $(this).attr('style', 'background-color:deeppink');
            }
            else {
                $(this).attr('style', 'background-color:none');
                if (localStorage.getItem('selectedLink') == null) {
                    $('[id*=lnkAllProducts]').attr('style', 'background-color:deeppink');
                }
            }
        });
    }
</script>