How do I insert errors do normfit?

I have a data that contain large vector of observation and another vector of the error in each measurement. I want to fit the data to a normal distribution, how do I make matlab to consider the measurements error when she compute "normfit"?

[KSSV]

You can add errors to the observation data...so that you get actual data..and then use this data to normfit......? isn't it?

[avner yakov]

What do you mean by "add errors to the observation data"? error of measurements are interval and not one number.