javascript - Adding select/deselect all to dynamic tabular form -

i have form contains buttons add , delete rows. javascript function check checkboxes works first row, once add more rows form, first row still 1 gets checked.

any tips?

here javascript function:

<code> //checks rows function checkall() { var mastercheck = document.getelementbyid('mastercheck'); var on = false; if(mastercheck.checked==true) {     document.getelementbyid('checkbox').checked=true; } else {     document.getelementbyid('checkbox').checked=false; } } </code> 

and here form: http://crimsonroot.com/files/freelance/new.html

any appreciated!

i found out wrong! @mohammed answer helped. there 1 or 2 syntax errors found. in order check , uncheck of boxes, needed add boolean variable input function follows:

//checks rows function checkall(bool) {     var mastercheck = document.getelementbyid('mastercheck');     var allcheck = document.getelementsbyclassname('checkbox');     var on = false;     (var = 0; < allcheck.length; i++) {         if (mastercheck.checked == true) {             allcheck[i].checked = true;         } else {             allcheck[i].checked = false;         }     }  }  

for reason, final piece puzzle. of help!