1. At a computer system, a method for mapping a breakpoint in one Web based document to another Web based document, the method comprising: an act of receiving a first Web based document including one or more client script blocks at one or more locations within the first Web based document; an act of receiving an indication that a breakpoint was inserted at a specified location within one of the one or more client script blocks in the first Web based document; an act of receiving a second Web based document including the one or more client scripts at one or more locations within the second Web based document; an act of parsing the first Web based document to separate the one or more client script blocks from other content in the first Web based document; an act of parsing the second Web based document to separate the one or more client script blocks from other content in the second Web based document; an act of extracting the separated one or more client script blocks from other content in the first Web based document; an act of extracting the separated one or more client script blocks from other content in the second Web based document; an act of mapping the breakpoint in the first Web based document to a corresponding appropriate location in the second Web based document based on the extracted one or more client script blocks from the first Web based document, the extracted one or more client script blocks from the second Web based document, and the specified location of the breakpoint within the client script block in the first Web based document; and an act of inserting the breakpoint into second Web based document at the mapped location such that execution of the second Web based document is halted in an appropriate location within the one or more client script blocks when the breakpoint is reached during processing of the second Web based document.