I Have A Database Having Isdeleted Field And Datatype Is Bit I Want To Change The Bit Value On Button Click In Gridview ?

1) first of all make modification on your select data query for gridview to display only those records which having IsDeleted = false

select......
.........
Where IsDeleted = 0

2) second create a web method which will called by clicking on your gridview's button click, and that web method is responsible to change your database table record related to Is Delete flag. call that web method using jquery ajax call, and on sucess of ajax call, find your gridview row and set it's css property to display none or something like that to hide the row.

[System.Web.Services.WebMethod]
public static string SetIsDeleted(string id)
{
    //Write your logic to update database entry with IsDeleted flag to false (0)
}

<script type = "text/javascript">
var id = 1; --write your own logic to get id for which you need to set IsDeleted flag
function ShowCurrentTime() {
    $.ajax({
        type: "POST",
        url: "Default.aspx/SetIsDeleted",
        data: '{id: "'+ id  + '"}',
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: OnSuccess,
        failure: function(response) {
            alert(response.d);
        }
    });
}
function OnSuccess(response) {
    //write logic to display none your grid view row
}


</script>

please check link[^] to check how to define and consume web method of aspx page.

Also please check this Link[^] too, that article is demonstrating how to delete record from gird view as well as database, you just need to follow all the steps and change logic just like instead of deleting record you need to write your query in such a way to just set IsDeleted column value.