Zoho Recruit API

Zoho Recruit API

Hi,

 

Now I am using the authentication token for connecting Zoho Recruit using VB.NET .... While using method to get the Authentication token it shows response as

 
#
   
#Fri Feb 08 11:52:37 PST 2013
   
CAUSE=EXCEEDED_MAXIMUM_ALLOWED_AUTHTOKENS
   
RESULT=FALSE
   

 

How many API requests per day can I do?  How can I renew or delete the Authtoken?