Can we draw mutlipath different width and spacing at the same time?

I'm not sure what you need to know about making it technology independent. It's just a matter of not hardcoding the layers and rules into the code, but either have them specified on the form or have them seeded from some external variables (or even maybe the technology file). The same is true to compute the layer above and layer below - you could either do this either by assuming that the metal layers are called xxxxxN with a number at the end, or looking at info in the technology file (using the tech.* functions) to look at the layers. For example:

techGetLayerFunctions(techGetTechFile(cvId))
(("Psub" "pwell" 1)
    ("Nburied" "nwell" 2)
    ("Nwell" "nwell" 3)
    ("Oxide" "ndiff" 4)
    ("Oxide_thk" "ndiff" 5)
    ("Poly" "poly" 6)
    ("Nhvt" "nplus" 7)
    ("Nimp" "nplus" 8)
    ("Phvt" "pplus" 9)
    ("Pimp" "pplus" 10)
    ("Nzvt" "nplus" 11)
    ("SiProt" "pplus" 12)
    ("Cont" "cut" 13)
    ("Metal1" "metal" 14)
    ("Via1" "cut" 15)
    ("Metal2" "metal" 16)
    ("Via2" "cut" 17)
    ("Metal3" "metal" 18)
    ("Via3" "cut" 19)
    ("Metal4" "metal" 20)
    ("Via4" "cut" 21)
    ("Metal5" "metal" 22)
    ("Via5" "cut" 23)
    ("Metal6" "metal" 24)
    ("Via6" "cut" 25)
    ("Metal7" "metal" 26)
    ("Via7" "cut" 27)
    ("Metal8" "metal" 28)
    ("Via8" "cut" 29)
    ("Metal9" "metal" 30)
    ("Bondpad" "unknown" 31)
    ("substrate" "recognition")
)

I could then use this to find the metal layer below or after (if it exists) and the via layers to use. You could also look up other rules in the tech file, should you want to. If there's no higher (or lower) layer, you could either ensure that the form didn't offer that choice of metal layer for the routing layer (you could add a cyclic field only containing the valid layers, which would then stop the user from being able to select a layer too high or too low in the stack). 

Not sure why you have put errset() around the entire code. That sounds a good way of making your code hard to debug when you make a mistake as it will suppress errors that you've made!

Regards,

Andrew.

I'm not sure what you need to know about making it technology independent. It's just a matter of not hardcoding the layers and rules into the code, but either have them specified on the form or have them seeded from some external variables (or even maybe the technology file). The same is true to compute the layer above and layer below - you could either do this either by assuming that the metal layers are called xxxxxN with a number at the end, or looking at info in the technology file (using the tech.* functions) to look at the layers. For example:

techGetLayerFunctions(techGetTechFile(cvId))
(("Psub" "pwell" 1)
    ("Nburied" "nwell" 2)
    ("Nwell" "nwell" 3)
    ("Oxide" "ndiff" 4)
    ("Oxide_thk" "ndiff" 5)
    ("Poly" "poly" 6)
    ("Nhvt" "nplus" 7)
    ("Nimp" "nplus" 8)
    ("Phvt" "pplus" 9)
    ("Pimp" "pplus" 10)
    ("Nzvt" "nplus" 11)
    ("SiProt" "pplus" 12)
    ("Cont" "cut" 13)
    ("Metal1" "metal" 14)
    ("Via1" "cut" 15)
    ("Metal2" "metal" 16)
    ("Via2" "cut" 17)
    ("Metal3" "metal" 18)
    ("Via3" "cut" 19)
    ("Metal4" "metal" 20)
    ("Via4" "cut" 21)
    ("Metal5" "metal" 22)
    ("Via5" "cut" 23)
    ("Metal6" "metal" 24)
    ("Via6" "cut" 25)
    ("Metal7" "metal" 26)
    ("Via7" "cut" 27)
    ("Metal8" "metal" 28)
    ("Via8" "cut" 29)
    ("Metal9" "metal" 30)
    ("Bondpad" "unknown" 31)
    ("substrate" "recognition")
)

I could then use this to find the metal layer below or after (if it exists) and the via layers to use. You could also look up other rules in the tech file, should you want to. If there's no higher (or lower) layer, you could either ensure that the form didn't offer that choice of metal layer for the routing layer (you could add a cyclic field only containing the valid layers, which would then stop the user from being able to select a layer too high or too low in the stack). 

Not sure why you have put errset() around the entire code. That sounds a good way of making your code hard to debug when you make a mistake as it will suppress errors that you've made!

Regards,

Andrew.