Sorry, the title probably sounds a little confusing, but hopefully my problem is a quick fix.

I have some charts, and in them about 6 different series. Along the x axis, is a bunch of different values, and each series has some values corresponding to some of the x axis values, but not all.

So basically right now, some series have gaps, and rather than connect the gaps with a line, Excel seems to just leave a gap in the series, and continue again at the next data point.

Hopefully you understand what I'm saying. Is there an easy way to just fill in these series gaps with a straight line connect the two closest data points to make the series continuous?

Thanks in advance for any help.