i have this expression to allow numbers and uppercase and lowercase letters and i also need to allow characters like - (minus) and _ (underline) and no white spaces can anyone help me with this please
if(txt1_len == 0 || txt1_len > 16 || txt1_len < 16 || !text1.value.match(
/^(?=.*[a-zA-Z])(?=.*\d)[a-zA-z\d]*$/))
the characters - and _ must not be mandatory but can be accepted. whitespace must not be accepted at all
thank you