Important: You must allow Excel macros to be enabled or none of the Zplots buttons will work. Please see "Understanding Excel Macro Virus Warnings" at ... http://www.ac6la.com/adhoc/vcheck.html ... for more details. Excel 2007 users: You must have Service Pack 2 installed. Click the Office Button > Excel Options > Resources. If you do not see "SP2" in the "About" section, click the Check for Updates button to download the required updates. Zplots will not operate correctly under earlier releases of Excel 2007. Zplots does not work with other spreadsheet software such as Open Office Calc, Quattro Pro, Microsoft Works, or versions of Excel earlier than Excel 97. None of these other spreadsheet programs fully support the macros used by Zplots. Note to international users: You need not make any changes to your Control Panel Regional Settings for language or number format in order to use Zplots with the comma-separated-values (*.csv) files from the supported programs. Zplots will read these files correctly even though they are formatted with a period as the decimal point and commas as field separators. Dan Maguire AC6LA http://www.ac6la.com/zplots.html