Bug 155365 Can not set data type to "date time" when editing "Data Item"
Description: Can not set data type to "date time" when editing "Data Item" Steps to reproduce: 1. Insert a data item to the layout 2. Name it and set the expression to "a = new Date()" 3. Select the data type to date time 4. Press ok Actual result: An Birt Exception is thrown out. Expected result: No NPE thrown out
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dialogs/DataItemBindingDialog.java
protected String expression;
	private Combo itemType;
	private Text itemName;
	private Combo itemAggregateOn;
	private Text itemExpression;
	private String typeSelect;
	private String nameSelect;
	private String aggregateOnSelect;
	private Label aggregateOnLabel;
	private Label hiddenLabel;
	protected ComputedColumnHandle bindingColumn;
	public DataItemBindingDialog( )
	{
		super( NEW_DATAITEM_TITLE );
	}
	public DataItemBindingDialog( String title )
	{
		super( title );
	}
	protected String[] convertListToStrings( List list )
	{
		if ( list == null )
			return null;
		String[] strings = new String[list.size( )];
		for ( int i = 0; i < list.size( ); i++ )
		{
			strings[i] = list.get( i ).toString( );
		}
		return strings;
	}