diff --git a/utils.ts b/utils.ts
new file mode 100644
index 0000000..edacc27
--- /dev/null
+++ b/utils.ts
@@ -0,0 +1,29 @@
+import { Login } from "@/types.ts"
+
+export function toLogin({
+	firstname,
+	lastname,
+}: {
+	firstname: string
+	lastname: string
+}): Login {
+	return `${sanitizeString(firstname)}.${sanitizeString(lastname)}`
+}
+
+export function sanitizeString(str: string): string {
+	return str.toLocaleLowerCase().split('').map(sanitizeChar).join('')
+}
+
+function sanitizeChar(char: string): string {
+	//decompose unicode and remove diacritical marks
+	char = char.normalize('NFD').replace(/[\u0300-\u036f]/g, '')
+	if (char.match(/[a-zA-Z0-9]|-|_/)) return char
+	return '_'
+}
+
+export const regex = {
+	uuidV4: /^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/,
+	isoDateString:
+		/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d+Z$/,
+	mailAddress: /\S+@\S+\.\S+/,
+}