1. A method for creating a CSS (cascading style sheet) file from a CSSX (Extended Cascading Style Sheets) file including CSSX extensions for defining a variable, said CSS file intended for execution by a web browser that does not execute CSSX extensions wherein the web browser would not execute the variables of the CSSX file including the CSSX extensions, comprising: creating the CSSX file including CSSX extensions for defining a variable and CSSX extensions for referencing said variable; determining a value of the defined variable in the CSSX file; modifying the CSSX file by replacing all references to the defined variable with the determined value; and generating from the modified CSSX file the CSS file not including the variable and including the replaced variable value wherein the CSS file contains only CSS compatible commands and wherein the CSS file contains no CSSX extensions.