abstract name checked to regex

mutt-wizard.sh

@@ -145,7 +145,11 @@ $serverinfo
 EOF
 fi
 realname=$( dialog --title "Luke's mutt/offlineIMAP autoconfig" --inputbox "Enter the full name you'd like to be identified by on this email account." 10 60 3>&1 1>&2 2>&3 3>&- )
-title=$( dialog --title "Luke's mutt/offlineIMAP autoconfig" --inputbox "Give a short, one-word name for this email account that will differentiate it from other email accounts." 10 60 3>&1 1>&2 2>&3 3>&- )
+title=$(dialog --title "Luke's mutt/offlineIMAP autoconfig" --inputbox "Give a short, one-word name for this email account that will differentiate it from other email accounts." 10 60 3>&1 1>&2 2>&3 3>&1) || exit
+namere="^[a-z_][a-z0-9_-]*$"
+while ! [[ "${title}" =~ ${namere} ]]; do
+	title=$(dialog --no-cancel --title "Luke's mutt/offlineIMAP autoconfig" --inputbox "Account title not valid. Give a username beginning with a letter, with only lowercase letters, - or _." 10 60 3>&1 1>&2 2>&3 3>&1)
+done
 login=$(dialog --title "Luke's mutt/offlineIMAP autoconfig" --inputbox "If you have a username for the \"$title\" account which is different from your email address, enter it here. Otherwise leave this prompt blank." 10 60 3>&1 1>&2 2>&3 3>&- )
 # Sets the repo type and other variables for the sed regex.
 if [[ "$service" == "gmail.com" ]];