calculating time duration

Hi,
currenttime1 & currenttime2 are assigned as current time. Both the time is same value. U'll use Current time is assigned to textbox1.text(when u store the start time). Then It'll Works. 
If ASP.Net means store it in session or hidden value field for the start time...
 
Regards,
Meha
 

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

public partial class SUBOK : System.Web.UI.Page
{  
   
    protected void Page_Load(object sender, EventArgs e)
    {


        System.Threading.Thread.Sleep(100);
        string currenttime = DateTime.Now.ToLongTimeString();
        string showDate = DateTime.Now.ToLongDateString();
        lblcurrenttime.Text = currenttime;
        lblshowDate.Text = showDate;
        
    }
 
 



    protected void GridView2_SelectedIndexChanged(object sender, EventArgs e)
    {

    }



    protected void Button3_Click(object sender, EventArgs e)
    {
         string currenttime1 = DateTime.Now.ToLongTimeString();
         TextBox1.Text = currenttime1;
    }
    protected void Button4_Click(object sender, EventArgs e)
    {
        DateTime dt1;
        DateTime dt2;

        string currenttime1 = DateTime.Now.ToLongTimeString();
        string currenttime2 = DateTime.Now.ToLongTimeString();
        TextBox2.Text = currenttime2;

        dt1 = Convert.ToDateTime(currenttime1);
        dt2 = Convert.ToDateTime(currenttime2);


        TimeSpan ts = dt1 - dt2;

        int min = Convert.ToInt32(ts.Minutes);
       
       

       
        string finalMin = Convert.ToString(min);


        TextBox3.Text = finalMin;
        
       


       

    }
} 










---thank you sir

Then the code you posted is not the code you are using in your program. Please post the correct code. In the code you posted, currenttime1 is not from the time when a different button was clicked; in the code you posted, both currenttime1 and currenttime2 have the time that Button4 was clicked.

No sir....

ahm.. the currenttime1 is from the time that was get when the START button is clicked. for example, i clicked the start button at time: 10:03 pm... so currenttime1 is: 10:03 pm... i clicked the STOP button at 11:00 pm.. currenttime2 is now 11:00.

the code i posted is just a part of the whole program sir