function checkuser(fld) {
var error = "";
var greska=0;
var illegalChars = /\W/; // allow letters, numbers, and underscores
if (fld.value == "") {
fld.style.background = 'Yellow';
error = "You didn't enter a username.\n";
greska=1;
//alert(error);
} else if ((fld.value.length < 5) || (fld.value.length > 15)) {
fld.style.background = 'Yellow';
error = "The username is the wrong length.\n";
greska=1;
//alert(error);
} else if (illegalChars.test(fld.value)) {
fld.style.background = 'Yellow';
error = "The username contains illegal characters.\n";
greska=1;
//alert(error);
} else {
fld.style.background = 'White';
}
if(greska) alert(error);
return error;
}
kako da blokiram submit ako validacija ne prodje?