I get the wrong result using IBK in weka - weka

Question

I have two data set, one for training data set and another for test data set.
I want to find the first nearest neighbor of the first instance of test data set among training data set, I wrote the following code:
data.setClassIndex(data.numAttributes() - 1);
data1.setClassIndex(data1.numAttributes() - 1);
IBk knn = new IBk();
String[] options = new String[2];
options[0]= "-E";
options[1]= "-I";
knn.setOptions(options);
knn.setKNN(1);
knn.setCrossValidate(true);
knn.buildClassifier(data);
int d = knn.getKNN();
Double c = knn.classifyInstance(data1.instance(0));
System.out.println(d);
System.out.println(c);
I don't know why I get the wrong result. Because the instance that I am looking for the nearest neighbor for, is in training set as well and the result should be the same value as the test instance , but it is not!
My Training dataset:
#relation MyRelation
#attribute Fname {Tina,Alex,Poul,Johan,Sarah}
#attribute Lname {Sansed,Erikson,Nadi,Raj,Maad}
#attribute Status {Single,Maried}
#attribute sex {Fmale,male}
#attribute 'worked years' numeric
#attribute age numeric
#attribute Adults numeric
#attribute tax numeric
#attribute salary numeric
#data
Tina,Sansed,Single,Fmale,14,35,5,362.79,1332.5
Alex,Erikson,Maried,male,14,40,6,0,1245.3
Poul,Nadi,Maried,male,6,35,6,207.32,1150.8
Johan,Raj,Maried,male,29,48,5,0,959
Sarah,Maad,Single,Fmale,16,42,2,0,667.1
Now in Test data set I want to determine the nearest neighbor for instance:
Johan,Raj,Maried,male,29,48,5,0,959
The Result of running the code is:
1
1332.5
It gives me the first instance of the training set every time that I try!