help me please please pleasa

I want import data from sqlserver to excel ;

When I click on the button I have no results,where is the problem
file: default.aspx.cs

using System;

using System.Drawing;

using System.Data;

using System.Data.SqlClient;

public partial class Default4 : System.Web.UI.Page

{

 

private System.Data.DataTable GetData()

{

SqlConnection conn = new SqlConnection(@"server=(.\SQLEXPRESS);uid=sa;pwd=xxxx;database=examen.mdf;");

SqlDataAdapter adapter = new SqlDataAdapter("select * from ETUDIANT", conn);

DataSet myDataSet = new DataSet();

try

{

adapter.Fill(myDataSet, "ETUDIANT");

}

catch (Exception ex)

{

 

}

return myDataSet.Tables[1];

}

private void button1_Click(object sender, System.EventArgs e)

{

Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();

int rowIndex = 1;

int colIndex = 0;

excel.Application.Workbooks.Add(true);

DataTable table = GetData();

foreach (DataColumn col in table.Columns)

{

colIndex++;

excel.Cells[1, colIndex] = col.ColumnName;

}

foreach (DataRow row in table.Rows)

{

rowIndex++;

colIndex = 0;

foreach (DataColumn col in table.Columns)

{

colIndex++;

excel.Cells[rowIndex, colIndex] = row[col.ColumnName].ToString();

}

}

excel.Visible = true;

}

 

}