how to solve the error in cognitive radio matlab code ? the error is ??? Operands to the || and && operators must be convertible to logical scalar values.

in_p = input('\nDo you want to enter a secondary user Y/N: ','s');

if(in_p == 'Y' in_p == 'y')

tp=0;

chek1 = Pxx(25)*10000;

chek2 = Pxx(46)*10000;

chek3 = Pxx(62)*10000;

chek4 = Pxx(89)*10000;

chek5 = Pxx(105)*10000;

if(chek1 && t==8000)

where t = 0:0.00001:0.01

error is

??? Operands to the and && operators must be convertible to logical scalar values.

Error in ==> cognradio at 89 if(chek1 && t==8000)