var ch = 'A';
if (islower(ch))
document.write("yes<br />");
else
document.write("no<br />");
var ch = 'a';
if (islower(ch))
document.write("yes<br />");
else
document.write("no<br />");
function islower(ch){
return ch == ch.toLowerCase() && ch !== ch.toUpperCase()
}
/*
run:
no
yes
*/