c# - Passing a Datatable From One Form to Another Form -

i have form1 , form2. form2 opened form1, has dgv after filling it, it's copied datatable on click button, , form2 closed or visible = false. passed datatable form1 it's giving me null reference. here code in form2:

private void button1_click(object sender, eventargs e)         {             perclothesdescriptiondt = new datatable();              foreach (datagridviewcolumn col in datagridview3.columns)             {                 perclothesdescriptiondt.columns.add(col.headertext);             }              foreach (datagridviewrow row in datagridview3.rows)             {                 datarow drow = perclothesdescriptiondt.newrow();                 foreach (datagridviewcell cell in row.cells)                 {                     drow[cell.columnindex] = cell.value;                 }                 perclothesdescriptiondt.columns.removeat(0);                 perclothesdescriptiondt.rows.add(drow);             }             this.visible = false;          }          public datatable mydt         {                         {                 return perclothesdescriptiondt;             }         } 

in form1:

form2= new form2();                  cmd1.commandtext = "insert [dbo].[personclothesdesc](upperpart, lowerpart, belt, socks, shoes, differentsigns) values (@upperpart, @lowerpart, @belt, @socks, @shoes, @differentsigns)";                         (int = 0; < form2.mydt.rows.count; i++)                         {                             cmd1.parameters.clear();                             cmd1.parameters.addwithvalue("@upperpart", form2.mydt.rows[i].itemarray.getvalue(5).tostring());                             cmd1.parameters.addwithvalue("@lowerpart", form2.mydt.rows[i].itemarray.getvalue(4).tostring());                             cmd1.parameters.addwithvalue("@belt", form2.mydt.rows[i].itemarray.getvalue(3).tostring());                             cmd1.parameters.addwithvalue("@socks", form2.mydt.rows[i].itemarray.getvalue(2).tostring());                             cmd1.parameters.addwithvalue("@shoes", form2.mydt.rows[i].itemarray.getvalue(1).tostring());                             cmd1.parameters.addwithvalue("@differentsigns", form2.mydt.rows[i].itemarray.getvalue(0).tostring());                             cmd1.executenonquery();                         }