Bug 132786 Value2 should be cleaned after convert operator from between to equal in highlight rule.
Description: Value2 should be cleaned after convert operator from between to equal in highlight rule. Steps to reproduce: 1. Insert a data. 2. Set highlight rule in Property Editor. 2 between 1 and 3, color blue. 3. Save the report 4. Modify highlight rule, change to 1 equal 1, color blue. 5. Save the report, see generated xml source. Expected result: In xml source, value2 should be cleaned in highlight expression. Actual result: In xml source, value1 is 1 and value2 is 3.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/HighlightRuleHandle.java
*/
	public void setDateTimeFormatCategory( String pattern )
			throws SemanticException
	{
		setFormatValue( HighlightRule.DATE_TIME_FORMAT_MEMBER,
				FormatValue.CATEGORY_MEMBER, pattern );
	}
	/**
	 * Sets the category/pattern value for a string/number/date-time format.
	 * 
	 * @param propName
	 *            the property name
	 * @param memberName
	 *            the category or pattern member name
	 * @param valueToSet
	 *            the value to set
	 * @throws SemanticException
	 *             if the category is not one of BIRT defined.
	 */
	private void setFormatValue( String propName, String memberName,
			String valueToSet ) throws SemanticException
	{
		Object value = getProperty( propName );
		FormatValue formatValueToSet = null;
		if ( value == null )
		{
			if ( HighlightRule.DATE_TIME_FORMAT_MEMBER
					.equalsIgnoreCase( propName ) )
				formatValueToSet = new DateTimeFormatValue( );
			else if ( HighlightRule.NUMBER_FORMAT_MEMBER