javascript - Check All won't work in Chrome but works in Firefox -

i have check box wherein when user tick it, items under ticked. works fine in firefox won't perform check function in chrome.

this js function:

function check(chk, num)    {        if(chk.value=="check all"){            (i = 0; <= num; i++){                chk[i].checked = true ;            }         chk.value="uncheck all";        }else{          (i = 0; <= num; i++){             chk[i].checked = false ;         }         chk.value="check all";     } } 

html:

<form target="_blank" action="" method="post" id="myform" name="myform">      <input type="checkbox" value="check all" onclick="check(document.myform.product a, 9)" id="fujitsu" name="fujitsu"> select      <input type="hidden" value="1" name="product_id[1]">      <input type="checkbox" value="product 1" id="product 1" name="product[1]">product -product 1      <input type="hidden" value="2" name="product_id[2]">      <input type="checkbox" value="product 2" id="product 2" name="product[1]">product -product 2  </form> 

for me both firefox , chromium crash on "document.myform.product a". here code little modified work:

function check(form, all, chk, num) {     if(form[all].value=="check all"){         (i = 1; <= num; i++){             form[chk + i].checked = true ;         }         form[all].value="uncheck all";     }else{          (i = 1; <= num; i++){             form[chk + i].checked = false ;         }         form[all].value="check all";     } } 

and html:

<form target="_blank" action="" method="post" id="myform" name="myform">-     <input type="checkbox" value="check all" onclick="check(document.myform, 'fujitsu',  'product_' , 2)" id="fujitsu" name="fujitsu"> select all-     <input type="hidden" value="1" name="product_id[1]">-     <input type="checkbox" value="product 1" id="product_1" name="product[1]">product -product 1-     <input type="hidden" value="2" name="product_id[2]">-     <input type="checkbox" value="product 2" id="product_2" name="product[1]">product -product 2- </form> 

but can cleaner code same thing:

function check(form, action) {     var l = form.getelementsbytagname("input");     (var = 0; < l.length; ++i)         if (l[i].type == "checkbox") l[i].checked = action; } 

and html:

<form target="_blank" action="" method="post" id="myform" name="myform">-     <input type="checkbox" value="check all" onclick="check(document.myform, this.checked)" id="fujitsu" name="fujitsu"> select all-     <input type="hidden" value="1" name="product_id[1]">-     <input type="checkbox" value="product 1" id="product_1" name="product[1]">product -product 1-     <input type="hidden" value="2" name="product_id[2]">-     <input type="checkbox" value="product 2" id="product_2" name="product[1]">product -product 2- </form> 

it better if used library css selectors jquery.