iDistance Optional. Integer爐hat specifies the number of URLs to go back. If no value is provided, the previous URL is loaded.
Return Value
No return value.
Remarks
This method performs the same action as when a user clicks the Back button in the browser. The back method works the same as history.go(-1). An error does not occur if the user tries to go beyond the beginning of the history. Instead, the user remains at the current page.