Modifying Error Bars (using ErrorListPlot)

Questions
1

Hi, does anyone know how to change the width of the error bars produced using ErrorListPlot?
Here is the table of data I’m using

  ppy = Table[{{(k + 574)*2 \[Pi]/(1*4000), pmy[[k]]}, 
        ErrorBar[sdy[[k]]]}, {k, 1, 191}];

Then I write

ErrorListPlot[ppy, PlotMarkers -> {Automatic, 1.5}

I can’t seem to change the width of the error bars produced. Any ideas?

2

My MMa 7 does not have ErrorListPlot. Reading the documentation suggests that an option like Filling → { } might work? My apologies that its only a suggestion that i can’t quite verify.