Invalid Combiantion of Leave

Hi,

Here v configured ESS. As per the requirement, If v apply casual leave today...next day v shouldnt apply any other leave other than casual. In the same way for all leaves.. Combination is compulsary..

V configured Workflow..

Present from portal if v apply leave in this combination ...it is working.

So, to make it to stop, do i need to configure it through work flow or through portal customization...

Can anyone plz. help me out of this problem...

Regards,

Venkat