function showTab(n) { // This function will display the specified tab of the form... var x = document.getElementsByClassName("tab"); x[n].style.display = "block"; //... and fix the Previous/Next buttons: if (n == 0) { document.getElementById("prevBtn").style.display = "none"; } else { document.getElementById("prevBtn").style.display = "inline"; } if (n == (x.length - 1)) { document.getElementById("nextBtn").innerHTML = "Отправить"; } else { document.getElementById("nextBtn").innerHTML = "Далее"; } //... and run a function that will display the correct step indicator: fixStepIndicator(n) }

function nextPrev(n) { // This function will figure out which tab to display var x = document.getElementsByClassName("tab"); // Exit the function if any field in the current tab is invalid: if (n == 1 && !validateForm()) return false; // Hide the current tab: x[currentTab].style.display = "none"; // Increase or decrease the current tab by 1: currentTab = currentTab + n; // if you have reached the end of the form... if (currentTab >= x.length) { // ... the form gets submitted: document.getElementById("regViForm").submit(); return false; } // Otherwise, display the correct tab: showTab(currentTab); }

function validateForm() { // This function deals with validation of the form fields var x, y, i, valid = true; x = document.getElementsByClassName("tab"); y = x[currentTab].getElementsByTagName("input"); // A loop that checks every input field in the current tab: for (i = 0; i