Because the object model never holds on to a text range, you'll need to re-create any range whenever control leaves and then reenters your code. For example, any text range objects created by an event handler are discarded when the event handler returns.
You can determine whether one range is entirely contained within another text range by using the inRange method. You can determine whether two text ranges are identical by using the isEqual method. Text ranges are identical if they start and end at exactly the same positions. Note that identical text ranges are always considered to be within one another, meaning the inRange method returns true for these.
You can set the start or end point of a range to match the start or end point of another range by using the setEndPoint method. The method takes two parameters: a string describing which end points to transfer, and a range from which the source end point is taken. The following example sets the end of the range r1 to the start of r2.
r1.setEndPoint( "StartToEnd", r2 )
You can also use StartToStart, EndToStart, and EndToEnd to set the end points.
You can compare the start or end points of two ranges by using the compareEndPoints method. This method compares the end points and returns -1, 0, or 1, indicating whether the end point of the first range is less than, equal to, or greater than that of the second.
A bookmark is an easy way to save the current start and end positions of a text range and quickly restore these positions when you need them. You create a bookmark for a given range by using the getBookmark method, which returns an opaque string that uniquely identifies the bookmark. (Opaque means the string cannot be examined or modified.) You use the string with the moveToBookmark method to move the text range back to the same start and end positions as when the bookmark was created.
