stating this with plain javascript would be pure pain :)
i suggest using jQuery, eg:
$(':checkbox').click(function() {
var checkbox = $(this);
var row = checkbox.closest('tr');
var inputText = $('input[type=text]', row);
if (checkbox.is(':checked')) {
inputText.attr('readonly', 'readonly');
}
else {
inputText.removeAttr('readonly');
}
});
otherwise
function HandleClickOnCheckbox() {
var checkbox = this;
var row;
var iter = checkbox;
while (!row) {
iter = iter.parent;
if (iter == window) {
break;
}
if (iter.tagName == 'tr') {
row = iter;
break;
}
}
if (!row) {
alert('row not found');
return false;
}
var textBoxes = GetTextBoxes(row);
var method;
if (checkbox.checked) {
var disabledAttribute = document.createAttribute('disabled');
disabledAttribute.nodeValue = 'disabled';
method = function(textBox) {
textBox.setAttributeNode(disabledAttribute);
};
}
else {
method = function(textBox) {
textBox.removeAttribute('disabled', 0);
}
}
for (var i = 0; i < textBoxes.length; i++) {
var textBox = textBoxes[i];
method(textBox);
}
}
function GetTextBoxes(element) {
var textBoxes = new Array();
for (var i = 0; i < element.children.lenght; i++) {
var child = element.children[i];
if (child.tagName == 'input') {
if (child.type == 'text') {
textBoxes.push(child);
}
}
if (child.tagName == 'td') {
var childTextBoxes = GetTextBoxes(child);
if (childTextBoxes.length) {
for (var j = 0; j < childTextBoxes.length; j++) {
var childTextBox = childTextBoxes[j];
textBoxes.push(childTextBox);
}
}
}
}
return textBoxes;
}
this is not tested!