Open XML Schema Comparison Window
When opening a new XML Schema Comparison window, the XML Schema comparison is given a name of the form XMLSchemaComparisonX, where X is an integer indicating that XML Schema comparison's position in the sequence of XML Schema comparisons opened in the current DiffDog session. This name appears in a tab at the bottom of the window.
Note that the Compare XML Schemas command opens only the XML Schema Comparison window; it does not open any XML Schema within the window. The two XML Schemas to be compared must be opened subsequently in the components of the comparison window, one in each component.
To open an empty XML Schema Comparison window:
•Select the menu option File | Compare XML Schemas or click the Compare XML Schemas 
button in the Standard toolbar.