1) Open CSS dialog
2) Choose any CSS file
3) Begin to print the name of style class in current field manually.

First request: The list of classes with tne name begining from printed symbols should be displayed for selection

4) Enter the name of class in style Class field manually

Second request: If the Class with current name exist, CSS dialog should load properties of this Class and make a preview of existing Class in special tab automaticly

Third request: If the Class with current name doesn't exist in CSS file, CSS dialog should clear all properties of previous Class (if they had been before) and generate the preview of this Class automaticly (every change in properties of this Class should be registared by preview) but shouldn't create this Class in CSS file. From this point new request comes:

4-th request: We need to provide "Apply" button near "Clear" button for saving current changes in existing class or saving a new class in CSS file, but without closing of a dialog. New Class should appear in combo only after "Apply" button press.

Today we have a little problem:
STEP 1. Print the name of new CSS class
STEP 2. Set up few attributes (or press "Clear" button)
STEP 3. Print another name of CSS class
STEP 4. Make some changes in properties (or press Clear button)
STEP 5. Go to "Preview" tab
RESULT: We can observ both Classes (from STEP 1 and from STEP 3), but in CSS file we have only SAVED Classes. The Class from STEP 1 appears in combo, that shouldn't happen because we haven't saved this class, "Apply" button had to be pressed before.

5-th request: We have to be able to preview SAVED Classes of current CSS file and only one current editing Class (whenever is it existing or not, if we want to save it, "Apply" button will help us)

6-th request: If we want to save any changes in current edited class and when choose another class, we have always to press "Apply" button