Bug 205400 error displaying parameter in a table
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/validators/DataColumnNameValidator.java
*         Otherwise, <code>false</code>.
	 */
	private static boolean exists( List columns, String columnName )
	{
		if ( getColumn( columns, columnName ) == null )
			return false;
		return true;
	}
	/**
	 * Gets the column with the given expression bound the given list.
	 * 
	 * @param columns
	 *            the binding columns
	 * @param name
	 *            the column binding name
	 * @return the bound column
	 */
	public static ComputedColumn getColumn( List columns, String name )
	{
		if ( ( columns == null ) || ( columns.size( ) == 0 ) || name == null )
			return null;
		for ( int i = 0; i < columns.size( ); i++ )
		{
			ComputedColumn column = (ComputedColumn) columns.get( i );
			if ( name.equals( column.getName( ) ) )
				return column;
		}
		return null;
	}
}