Note the use of single quotation marks inside the parentheses, since the entire object is itself enclosed in the double quotes of the onClick script. The URL is the location of the document or image that you want to appear in the new window. The window features control the size, location, appearance, and other aspects of the pop-up window. They all appear in one set of single quotation marks. Use them to control the placement of the pop-up window relative to the upper left corner of the user's monitor.
Values are in terms of pixels.
Use them to control the placement of the pop-up window relative to the left and top edges of the user's monitor. Values are in terms of pixels. If you know the exact size of the image or document that will appear in your pop-up window, scrollbars are probably not needed. If you don't know the exact size or the size will vary, you should probably turn them on. Lastly, complete your hypertext reference in the usual way, placing either text or an image between the opening and closing anchor tags to finish the link.