Implementation of inserting a row at a specified position in the Javascript talbe table

Recently I learned Javascript. The following is an example (based on w3cschool)
In this example, a row is inserted after the row clicked by the mouse. By default, a row is inserted in the first row. You can enter the inserted content by yourself, CodeAs follows: <Br/> <Table id = "mytable" border = "1"> <tr> <TD> row1 cell1 </TD> <TD> row1 cell2 </TD>/ tr> <TD> row2 cell1 </TD> <TD> row2 cell2 </TD> </tr> <TD> row3 cell1 </TD> <TD> row3 cell2 </TD> </tr> </table> <p> cell1: <input type = "text" id = "cell1" value = "cell1" <br/> cell2: <input type = "text" id = "cell2" value = "cell2"> </P> <p> <input type = "button" onclick = "insrow () "value =" insert row ">