GridView Column Width and Wrap

Hello,

I have UnBound GridView - C# ASP.Net and I am refreshing this by query.
I have below code -

SqlDataAdapter adp = new SqlDataAdapter("Select Entry_Date, Emp_Name, Qunatity, Comments From Activity_Master", SqlCon);
System.Data.DataTable dt = new System.Data.DataTable();
adp.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();

I want to set Column width = 50 of "Comments" column and want Warp.

GridView1.Columns[3].ItemStyle.Width = 50;
      GridView1.Columns[3].ItemStyle.Wrap = true;

This gives me below error.

Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

How do resolve this. Please help.

Tags: C# (C# 4.0), ASP.NET