Bug 146159 [Regression]Changing font operation doesn't work other than the first time
Description: The first time changing operation can work well. However, Change it again, it won't work. Steps: 1.Insert lable/text to layout or master page 2.Change the font from serif to cursive, it works well 3.Change the font again Result: The action doesn't work Additional infor: build number:200606080632
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
{
			return true;
		}
		return false;
	}
	/**
	 * Create a row expression base on a binding column name.
	 * 
	 * @param columnName
	 *            the column name
	 * @return the expression, or null if the column name is blank.
	 */
	public static String getColumnExpression( String columnName )
	{
		Assert.isNotNull( columnName );
		if ( StringUtil.isBlank( columnName ) )
		{
			return null;
		}
		return IReportElementConstants.BINDING_COLUMN_PREFIX
				+ "[\"" + DEUtil.escape( columnName ) + "\"]";
	}
	/**
	 * Create a row expression base on a result set column name.
	 * 
	 * @param columnName
	 *            the column name
	 * @return the expression, or null if the column name is blank.
	 */
	public static String getResultSetColumnExpression( String columnName )