I have a question about beta coefficients that are calculated

for standard multiple linear regression procedure. I kind of don't understand

about how they indeed are calculated. They are regression coefficients

that occur when predictors are standardized to have zero mean and 1

standard error. I thought they are just raw coefficients multiplied by

corresponding raw predictor's standard errors. But it seems like it's not true.

Any thoughts on how they are calculated ?

Thanks in advance.