[Qgis-developer] How can delimeter percentage values?

[francescoboccacci at libero.it]

Hi all,
i'm using sextante plugin to develop a new algorithm. I would like to create a 
field as percentage  value (between 5 to 100). 
I'm using this line of code:

self.addParameter(ParameterNumber(MCP.PERCENT, "Percent of fixes", 5, 100, 
95))

but i'm not able to force to limit from 5 to 100 the new inserted number.
Where am i wrong?

Thanks

Francesco