Bug 151381 [Smoke]The parameter didn't display in the web viewer
Description: Preview a parameter in the web viewer, it can't be previewed. Step to reproduce: 1. new a report and a parameter 2. drag it to the layout 3. preview it in the web viewer Actual result: the parameter is not displayed
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/DataTypeUtil.java
else if ( source instanceof String )
		{
			try
			{
				return Double.valueOf( (String) source );
			}
			catch ( NumberFormatException e )
			{
				throw new BirtException( pluginId,
						ResourceConstants.CONVERT_FAILS,
						new Object[]{
								source.toString( ), "Double"
						},
						resourceBundle );
			}
		}
		else
		{
			throw new BirtException( pluginId,
					ResourceConstants.CONVERT_FAILS,
					new Object[]{
							source.toString( ), "Double"
					},
					resourceBundle );
		}
	}
	/**
	 * Number -> String
	 * 		Number.toString()
	 * Boolean -> String