I would use the "Mouse Up" action for the check box and set the readonly property of the text field based on the value of the check box.
Assuming you are using a single check box field named "ChecBox 1" and text field named "Text1" your mouse up action could be:
if(this.getField(event.target.name).value != "Off") {
// check box has been selected
this.getField("Text1").readonly = false;
} else {
// check box not selected
this.getField("Text1").readonly = true;
// option to clear the field if check box not selected
this.getField("Text1").value = "";
}
or
if(this.getField(event.target.name).isBoxChecked(0)) {
// check box has been selected
// make RW
this.getField("Text1").readonly = false;
} else {
// check box not selected
// option to clear the field if check box not selected
this.resetForm(["Text1"]);
// make read only
this.getField("Text1").readonly = true;
}
