Problem While using check boxes

[shyamkumar bopannachengalaiah]

Thanks for your suggestion . But the actual problem is that i have a five check boxes where first check box name is "all" and other four check box name is subject names and their values are different.when i click the " all " checkbox the other subjectname check boxes will be checked or selected.so it works finer when i have more than one subject name.but when i have single subject name and when i click the" all " check box it throws an error message as undefined length.so i need help for check box having "all" check box and a single subjectname checkbox.





I am working on a application where i have five check boxes.First checkbox name is 'All' and name for other four checkboxes are 'Subjectname'. if i have a screen where all five checkboxes are displayed when i check in first check box i am getting no problems. but when i have a screen displaying only 'All' check box and single subjectname check box when i click check in 'All' checkbox i am getting a alert message as undefined length.how can i solve this problem. i am using html and javascript.

<code>

function Check(tt)
{
//alert(tt.value);
if(document.Form1.Check_ctr.checked==true){
for (i = 0; i < ; i++)
//alert(tt[i].value);
tt[i].checked = true ;
}else{

for (i = 0; i < y; i++)
tt[i].checked = false ;
}
}


<input type="checkbox" name="Check_ctr" value="yes"
onClick="Check(checkbox1)">
<input type="checkbox" name="checkbox1" value="Subjectname1">

<input type="checkbox" name="checkbox1" value="Subjectname2">

<input type="checkbox" name="checkbox1" value="Subjectname3">

<input type="checkbox" name="checkbox1" value="Subjectname4">

<input type="checkbox" name="checkbox1" value="Subjectname5">


</code>

[chsanthosh kumar]

Hey,

ex1: http://www.somacon.com/p117.php
ex2: http://www.plus2net.com/javascript_tutorial/checkbox-checkall.php

however, you will find more examples in search...

[Eric Pascarello]

It has been asked many times on this forum: https://coderanch.com/t/116148/HTML-JavaScript/Select-All

Eric