Bug 182673 No default value error message prompts incorrectly
Steps to reproduce: 1. New a report parameter; 2. Choose control type as Combo; 3. Choose parameter as dynamic type; Expected result: As the isRequired is false by default, parameter's default value can be null value. There should be no error message about no default value prompt. Actual result; Error messages prompts
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
}
		try
		{
			getValue( value );
		}
		catch ( BirtException e )
		{
			return ERROR_MSG_MISMATCH_DATA_TYPE;
		}
		return null;
	}
	private boolean isEqual( String value1, String value2 )
	{
		Object v1 = null;
		Object v2 = null;
		try
		{
			v1 = getValue( value1 );
			v2 = getValue( value2 );
		}
		catch ( BirtException e )
		{
		}
		if ( v1 == null )
		{
			return v2 == null;
		}
		if ( v1 instanceof Double && v2 instanceof Double )
		{
			return ( (Double) v1 ).compareTo( (Double) v2 ) == 0;