Calculating Error Bars from Cftool

Hello,

I realize this is a super basic question (and also is just indicative of how little I know about statistics). In any case here is my problem: I have a single set of x- and y- data which I have performed linear regression on using the cftool:

[fitresult, gof, etc] = fit( xData, yData, 'poly1' );

I now simply want to plot the fit (accomplished) and error bars around each point. I believe there is a way to see the residuals from the fit, but I am not even sure how to begin turning this into he proper type of error bar. I also know how to use errorbar once I have a vector with all the calculated errors. My problem is really conceptual and statistical: how do I move from the fit to illustrating the error around each point.

Thanks! Noah