JSFiddle - React, Tailwind, and code Playground

HTML

<button id= "btn" onClick="" >Delete</button>

JavaScript

// protected void grdBooks_RowDataBound(object sender, GridViewRowEventArgs e)
//    {LinkButton lb = (LinkButton)e.Row.FindControl("LinkButton2");
//            lb.Attributes.Add("onclick", "return confirm('Are you //sure to delete book  " + DataBinder.Eval(e.Row.DataItem, "IName") + //"');");
//}

// instead of return confirm call this function

// After click on delete button it goes to web method with your itemid then you can delete or do what ever your operation
function showConfirm(itemId)
{
     var result = confirm('Are your sure want to delete this?');
        if(result == true)
        {
			// this is ajax method call
            
            // url is your page url and method is you need to create 			 // new web method, finally we send item id to web method 
            // 
            // refer this page http://www.aspsnippets.com/Articles/Calling-ASPNet-WebMethod-using-jQuery-AJAX.aspx
             $.ajax(
                {
                    type: 'Get',
                    url:'yourPage.aspx/WebMethod',
                    data : '{itemId : "' + itemId + '"}',
                    success : function(data)
                    {
                        alert('data');
                    },
                    error : function(xhr)
                    {
                        alert(xhr.responseText);
                    }
                });

        }
}