public string JsFunction_BeforeDocumentClosed { get; set; }

Public Property JsFunction_BeforeDocumentClosed As String
	Get
	Set

<asp:AceoffixCtrl JsFunction_BeforeDocumentClosed="String" />

Property Value

This event is triggered at the client-side before the document is closed.

If you want to capture this event, You should define a JavaScript function in the aspx file of current page.

In the JavaScript function, you can return false to prevent from closing the document.

But returning false can not prevent web browser from being closed. If you want to check whether current document is modified and notice user to save document before close page, we recommend you write code into onunload event of the page.

The following code example shows how to use the JsFunction_BeforeDocumentClosed property.

AceoffixCtrl1.JsFunction_BeforeDocumentClosed = "BeforeDocumentClosed()";

And then, you should define the BeforeDocumentClosed() JavaScript function in the aspx file of current page.

<script language="javascript" type="text/javascript">
    function BeforeDocumentClosed() {
        // Add your code here.
    }
</script>

Reference