Get lowest column value from two datatable in asp.net

//suppose you want to get minimum value of ID from dt1,dt2
DataTable dt1; // you already have values in this datatable
DataTable dt2; // you already have values in this datatable
DataTable dt3;
int minvalue1=0,minvalue2=0;
DataRow[] dr = dt1.Select("ID = Min(ID)");
if(dr != null && dr.Count() > 0)
{
      minvalue1 = Convert.ToInt32(dr.CopyToDataTable().Rows[0]["ID"]);
}
DataRow[] dr1 = dt2.Select("ID = Min(ID)");
if(dr1 != null && dr1.Count() > 0)
{
      minvalue2 = Convert.ToInt32(dr1.CopyToDataTable().Rows[0]["ID"]);
}
DataRow drNew = dt3.NewRow();
if(minvalue1 <= minvalue2)
{
      drNew["ID"] = minvalue1;
} 
else
{
      drNew["ID"] = minvalue2;
} 
dt3.Rows.Add(drNew);