Initial point selection in MLE of GARCH

I want to estimate a simple GARCH(1, 1) model with maximum likelihood estimation. I wrote the log likelihood function. I minimize the minus of it by using "fminunc" function. But I got different results for different initial values. My first question is that how can I selct the correct initial point?

I check the Econometrics Application of Matlab. It gives me good result but I want to understand how this app selects the inital point or how does it estimate?