Bug 177439 Need an easy way to determine default value for a dynamic parameter
Currently, I have to bring up the data set editor, preview the results in the data set and make a mental note of the value to use for a report parameter that depends on a data set. It would be nice to have a drop down on the default value field, such as <Select value> which when selected queries the data set and presents me with a list to select from.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
string = new NumberFormatter( pattern ).format( DataTypeUtil.toDouble( string )
						.doubleValue( ) );
			}
			else if ( DesignChoiceConstants.PARAM_TYPE_DECIMAL.equals( getSelectedDataType( ) ) )
			{
				string = new NumberFormatter( pattern ).format( DataTypeUtil.toBigDecimal( string ) );
			}
			else if ( DesignChoiceConstants.PARAM_TYPE_STRING.equals( getSelectedDataType( ) ) )
			{
				string = new StringFormatter( pattern ).format( string );
			}
		}
		catch ( BirtException e )
		{
			
		}
		return string;
	}
	/**
	 * Check if the specified value is valid
	 * 
	 * @param value
	 *            the value to check
	 * @return Returns the error message if the input value is invalid,or null
	 *         if it is valid
	 */
	private String isValidValue( String value )
	{
		if ( canBeNull( ) )
		{