allowed calculation once the form is valid

public/index.js

@@ -43,12 +43,13 @@ function setCharacterLength(characters) {
 }
 
 function calculateReadingTime() {
-    let isFormValid = validateForm();
-    let x = document.getElementById('calculate-time-element');
-    x.style.display = "block";
+    if (isFormValid()) {
+        let x = document.getElementById('calculate-time-element');
+        x.style.display = "block";
+    }
 }
 
-function validateForm() {
+function isFormValid() {
     let invalidFields = 0;
     if (inputObj.textChoice === 'manual' && inputObj.text === '') {
         invalidFields++;
@@ -77,7 +78,9 @@ function validateForm() {
     } else {
         document.getElementById('readerCategory-validation').style.display = 'none';
     }
-    
+
+    return invalidFields < 1
+
 }
 
 function showFeedbackForm() {