multiple lines in one graph with if conditions

[Lukas Nicht]

hi statalist,

I have the following data:

* Example generated by -dataex-. For more info, type help dataex
clear
input byte period float(time var1)
1 1 -.0004733252
1 2  -.003605119
1 3   -.02635961
1 4   -.02870885
1 5  -.029828776
2 1 -.0006582998
2 2 .00020854693
2 3   -.02371385
2 4   -.02286483
2 5    -.0230184
end
label values time t
label def t 1 "t-1", modify
label def t 2 "t", modify
label def t 3 "t+1", modify
label def t 4 "t+2", modify
label def t 5 "t+3", modify

I want to make a graph with two lines.
The first line should show var1 if period == 1 and the second line should show var1 if period == 2.
The first line should be a solid line, the second a dashed line.
x-axis should be time (t-1 to t+3), y-axis should be the values of var1.

I tried with twoway but unfortunately didn't work.
Any recommendation how to solve my problem?

[Fei Wang]

Lukas, you may try this code.

twoway line var1 time if period == 1, lp(solid) || line var1 time if period == 2, lp(dash) xlabel(,val) legend(order(1 "period 1" 2 "period 2"))