Bug 156166 Error occour when previewing attached report in web viewer.
Decription:Error occour when previewing attached report in web viewer. Steps to reproduce: 1.run attached reports in web viewer. Expeceted results: preview properly Actual results: Error occour when previewing the reports in web viewer while it works properly in html and PDF
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/BindingColumnsEvalUtil.java
* @param serviceForResultSet
	 */
	private void initBindingColumns( List manualBindingExprs,
			Map autoBindingExprs )
	{
		
		int size = manualBindingExprs.size( );
		GroupBindingColumn[] groupBindingColumns = new GroupBindingColumn[size];
		Iterator itr = manualBindingExprs.iterator( );
		while ( itr.hasNext( ) )
		{
			GroupBindingColumn temp = (GroupBindingColumn) itr.next( );
			groupBindingColumns[temp.getGroupLevel( )] = temp;
		}
		allManualBindingExprs = new ArrayList( );
		for ( int i = 0; i < size; i++ )
		{
			List groupBindingExprs = new ArrayList( );
			itr = groupBindingColumns[i].getColumnNames( ).iterator( );
			while ( itr.hasNext( ) )
			{
				String exprName = (String) itr.next( );
				IBaseExpression baseExpr = groupBindingColumns[i].getExpression( exprName );
				groupBindingExprs.add( new BindingColumn( exprName, baseExpr ) );
			}
			allManualBindingExprs.add( groupBindingExprs );
		}
		
		
		allAutoBindingExprs = new ArrayList( );