Bug 146796 Error message pop up if display text contain non-digital char when add next item
Description: In decimal type parameter creation,display type is "list box", Error message pop up if "display text" contain non-digital char when add next item. Steps: 1.Create a new decimal parameter 2.Set display type as "list box" 3.Input one item: value:1, display text:test 4.Input another item: Value:2 Actual result: error message pop up: The display text already exists! Expected result: Input item succussfully.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
public void dispose( )
		{
		}
		public boolean isLabelProperty( Object element, String property )
		{
			return false;
		}
		public void removeListener( ILabelProviderListener listener )
		{
		}
	};
	private ICellModifier cellModifier = new ICellModifier( ) {
		public boolean canModify( Object element, String property )
		{
			if ( property == null
					|| ( element == dummyChoice && !COLUMN_VALUE.equals( property ) ) )
			{
				return false;
			}
			return true;
		}
		public Object getValue( Object element, String property )
		{
			SelectionChoice choice = ( (SelectionChoice) element );
			if ( choice == dummyChoice )
			{
				return ""; 
			}