calssifying data using classifier

I have extracted the features of a brain images and have saved it a variable S

i have classified it using svm classifier

xdata is my features extratced variables,test is my test data

   svmStruct = svmtrain(xdata,groups,'showplot',true);

   s= svmclassify(svmStruct,test,'showplot',true)

in s i get output as 1 and 2,i want to classify it is normal images or tumour affected image,how do i classify it

please assit