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
newBinding.setExpression( itemExpression.getText( ) );
				if ( itemAggregateOn.isVisible( )
						&& !( itemAggregateOn.getText( ).equals( ALL ) || itemAggregateOn.getText( )
								.equals( NONE ) ) )
				{
					newBinding.setAggregateOn( itemAggregateOn.getText( ) );
				}
				else
					newBinding.setAggregateOn( null );
				bindingColumn = DEUtil.addColumn( getBindingObject( ),
						newBinding,
						isForceBinding( ) );
			}
			else
			{
				if ( !( bindingColumn.getName( ) != null && bindingColumn.getName( )
						.equals( itemName.getText( ).trim( ) ) ) )
					bindingColumn.setName( itemName.getText( ) );
				for ( int i = 0; i < DATA_TYPE_CHOICES.length; i++ )
				{
					if ( DATA_TYPE_CHOICES[i].getDisplayName( )
							.endsWith( itemType.getText( ) ) )
					{
						bindingColumn.setDataType( DATA_TYPE_CHOICES[i].getName( ) );
						break;
					}
				}
				bindingColumn.setExpression( itemExpression.getText( ) );
				if ( itemAggregateOn.isVisible( )
						&& !( itemAggregateOn.getText( ).equals( ALL ) || itemAggregateOn.getText( )