add your code at RowDataBound event. Then you get cell value.
In RowDataBound Event add following code.
declare a variable for store Row value.
<datatype> RowVal;
protected void CompanyGv1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType == DataControlRowType.DataRow)
{
RowVal = e.Row.Cells[1].Text.ToUpper();
}
}
And then pass this variable to your code.
protected void btncontact_Click(object sender, EventArgs e)
{
Response.Redirect("~/Admin/Company/Contact.aspx?CompanyName=" + RowVal );
}