Please visit this link to view the Comparison of Vowel markers in Tamil, Sourashtra, Telugu and Devanagari Scripts.
https://docs.google.com/open?id=0B4aElmOxci2aZTRaR2dzeWR5M3M
https://docs.google.com/open?id=0B4aElmOxci2aZTRaR2dzeWR5M3M
Learn Sourashtra language spoken in Madurai and in many towns of Tamil Nadu, Bangalore, Hyderabad, Mumbai, Delhi etc. place.