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
if ( content != null )
		{
			label.setText( content );
		}
		setLabelLayoutData( label );
	}
	private void setLabelLayoutData( Label label )
	{
		GridData gd = new GridData( );
		if ( label.getText( ).equals( LABEL_VALUES ) )
		{
			gd.verticalAlignment = GridData.BEGINNING;
		}
		label.setLayoutData( gd );
	}
	private void addCheckBoxListener( final Button checkBox, final String key )
	{
		checkBox.addSelectionListener( new SelectionAdapter( ) {
			public void widgetSelected( SelectionEvent e )
			{
				checkBoxChange( checkBox, key );
			}
		} );
	}
	/**
	 * @param key
	 * @param checkBox
	 * 
	 */
	protected void checkBoxChange( Button checkBox, String key )