only validate if input fields non-empty

js/index.js

@@ -128,28 +128,38 @@ validatePurpose = (target) => {
 }
 
 document.querySelector("#name input").addEventListener("input", (event) => {
+  if (event.target.value.length > 0) {
     validateName(event.target);
     regenerate();
+  }
 });
 
 document.querySelector("#iban input").addEventListener("input", (event) => {
+  if (event.target.value.length > 0) {
     validateIban(event.target);
     regenerate();
+  }
 });
 
 document.querySelector("#bic input").addEventListener("input", (event) => {
+  if (event.target.value.length > 0) {
     validateBic(event.target);
     regenerate();
+  }
 });
 
 document.querySelector("#amount input").addEventListener("input", (event) => {
+  if (event.target.value.length > 0) {
     validateAmount(event.target);
     regenerate();
+  }
 });
 
 document.querySelector("#purpose input").addEventListener("input", (event) => {
+  if (event.target.value.length > 0) {
     validatePurpose(event.target);
     regenerate();
+  }
 });
 
 // Remember inputs