Automatically save textbox contents

I have a textbox that a user can type some text into. The area that the textbox is in can get re-loaded with different HTML depending on what the user does, and I want the textbox to "remember" what the us开发者_开发知识库er typed into it when he comes back.

The problem starts with the fact that there are many different ways that the user can navigate away from the textbox - he can load many different HTML segments into my operational area, each erasing the textbox.

Is there a way for me to universally save textbox contents when it is getting unloaded? Is there an equivalent of onUnload() event for textbox?

There are two ways I can see that would solve my problem:

1. Setup textbox watchdog functions that update text stored in memory whenever user types anything.
2. Add a saveText() call to every function that reloads the operational area.

Neither of these is particularily appealing. Is there a more elegant way of doing this?

Thanks,

The onchange is what you're looking for. When the user exits the textbox, the change event is fired.

onchange is a better choice than onblur or focusout, because blur and focusout also fire when the contents of the text field hasn't changed.

A basic example:

var textarea = document.getElementById("myTextfield");
textarea.onchange = function(ev){
    call_function_that_saves(this.value);
}

An unload event for non-embedded elements doesn't exist. Consider what would happend when such an event handler exists, and a huge page unloads..