using of Multivariate ANOVA in measuring the goodness of fit

Hi, In some statistical analysis I have 3 sets of data and for each set there are two variables. Now in 'manova1' (y=manova1(X,GROUP, alpha)) program of MATLAB, each row of input 'X' matrix represents 1 observation and each column represents a variable. X values (row) are in the same group if they correspond to the same value of GROUP. In my case, I have two variables, lets say, p1 and p2 and 3 sets of data (each of 1000 samples). So what should be the input format (X and GROUP) of my case?

Should X be, X=[p11 p21 p12 p22 p13 p23] where each column length is 1000? In that case how can I build the GROUP input?