can i use to_ascii function ?

["j n" <jneuschld(at)gmail(dot)com>]

Hi 

i need to get rid of acute, and other special symbols from letters. Is any way how to do it easy in postgres ? 

i need conversion like this from slovak language ... :

é, ě -> e
á, ä -> a 
š -> s

i tried :

SELECT to_ascii('ščďť')

i get an error : ERROR:  encoding conversion from UTF8 to ASCII not supported

that i found something like this

SELECT convert('ščďť', 'UTF8', 'LATIN1')

i get an error : ERROR:  character 0xc5a1 of encoding "UTF8" has no equivalent in "LATIN1"

Is any way how to do it ? 
If there is not build in support for this conversion can i create my own ?

pls help