I saw a few things wrong with your code.
In the "for" loop, you don't declare i as a var. This could cause the
script to stop working.
You need to specify an action and a method in your form. Leaving them
blank is not an option. "action" is the next page or process in
sequence. "method" is usually either "POST" or "GET" - read up on
these to decide which to use.
--Tim Sabin
> Sorry for incovenience, i'd posted the same in portuguese list of
> javascript, but none of these members help me.
>
> Ok, i will describe my question now 
>
> I have some grups of radio buttons:
>
> <script type="text/javascript">
> function check_all(chks){
> for(var t = chks.value.length, i=0; i < t; i++) chks[i].checked =
true;
> }
> </script>
>
> <form name="dados" action="" method="">
>
> <input type="radio" name="presence[1]" value="Present" />
> <input type="radio" name="presence[1]" value="HalfTime" />
> <input type="radio" name="presence[1]" value="Saturday" />
> <input type="radio" name="presence[1]" value="Absent" />
>
> <input type="radio" name="presence[2]" value="Present" />
> <input type="radio" name="presence[2]" value="HalfTime" />
> <input type="radio" name="presence[2]" value="Saturday" />
> <input type="radio" name="presence[2]" value="Absent" />
>
> <input type="radio" name="presence[3]" value="Present" />
> <input type="radio" name="presence[3]" value="HalfTime" />
> <input type="radio" name="presence[3]" value="Saturday" />
> <input type="radio" name="presence[3]" value="Absent" />
>
> //I want here one button to select all "Present"
> //Another to all "HalfTime"
> //One another to all "Saturday"
> //And finally another to "Absent"
> //The function on top don't work, how can I do this ?
>
> // Best Regards For All Friends !!! =D
>
> <input type="button" value="Mark all"
> onclick="javascript:check_all(document.dados.elements
['Present']);" />
> <input type="button" value="Mark all ½"
> onclick="javascript:check_all(document.dados.elements
['HalfTime']);" />
> <input type="button" value="Mark All Saturday"
> onclick="javascript:check_all(document.dados.elements
['Saturday']);" />
> <input type="button" value="Mark All Absent"
> onclick="javascript:check_all(document.dados.elements['Absent']);" />
>
> <input type="submit" value="Submit" />
>
> </form>
>
>
>
>
>
> Visit http://aiaiai.com for more groups to join
> Yahoo! Groups Links
>
>
>
>
>
--Tim Sabin
.