accessing checkboxlist text through javascript - asp.net

Question

I have a checkbox list i have which i have bound some document name to it's text field.now i need to find only the checkboxes which the text contains the .pdf extension and check them all in a single checkbox click.i have written the following javascript but it doesn't work for me
function CheckAllPDF() {
var checkBoxList = document.getElementById("<%= cblFiles.ClientID %>");
var checkBoxes = checkBoxList.getElementsByTagName("input");
for (i = 0; i < checkBoxes.length; i++) {
var string = checkBoxes[i].parentNode.getElementsByTagName('label').innerHTML;
var match = string.indexOf(".pdf");
if (match != -1) {
checkBoxes[i].checked = true;
}
else {
checkBoxes[i].checked = false;
}
}
can some one help?

Answer 1

When you put an asp.net check box list in the page it is translated to a list of input of type checkbox so you need to access each control and check it so you javascript code should look like:
//Get the main id of the asp.net check box list
var checkboxId = '<%= CheckBoxList1.ClientID %>';
//Loop on all generated input check boxes where the count function determine the number of generated checkboxes
for (var i = 0; i < <%= Count() %>; i++) {
//Append the count on the main asp.net check box id the value ('_'+i)
var checkBox = document.getElementById(checkboxId + '_' + i);
var checkBoxValue = checkBox.value;
var match = checkBoxValue.indexOf(".pdf");
if (match != -1) {
checkBox.checked = true;
}
else {
checkBox.checked = false;
}
}
And in your code behind write the count function as follows:
public int Count()
{
return CheckBoxList1.Items.Count;
}