return string value... getting incompatible error

Hi can you not return a string value? i tried this and get incompatable error?

string ln=ln_txt[i];
return(ln);

if i print ln it prints string values fine but when i add it in return to transfer value from the called indicator in to my ea it gives incompatable error?

any ideas why

what datatype is ln_txt[]?

it is a string value

I tried below function, it worked.

string ReturnString(int i)
{
string ln_txt[3] = {"aaa", "bbb", "ccc"};
string ln=ln_txt[i];
return(ln);
}