function checkIfInputsExist (){ window.setTimeout(function(){ // Regular expression to check if string is email const regexExp = /^(([^<>()[\]\\.,;:\s@"]+(\.[^<>()[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/; // Grabs Email Address Value const learnerEmail = $("#learner_email")[0].value; // List of Emails to Block const blockedEmails = [ "gmail.com", "yahoo.com", "hotmail.com", "aol.com", "outlook.com", "icloud.com", "me.com", "mac.com" ] if ($("#learner_email")[0].value.length > 0){ if(regexExp.test(learnerEmail) == true){ var slicedEmail = learnerEmail.split('@'); if (blockedEmails.indexOf(slicedEmail[1]) > -1) { $("#learner_email").css("background", "salmon"); $("#bad_email_alert").css("color", "#f2f4f5"); $("#bad_email_alert").css("display", "block"); $("#submit_button").css("pointer-events","none"); } else { $("#learner_email").css("background", "#f2f4f5"); $("#bad_email_alert").css("display", "none"); $("#submit_button").css("pointer-events", "auto"); } } else { $("#learner_email").css("background", "#f2f4f5"); $("#bad_email_alert").css("display", "none"); $("#submit_button").css("pointer-events", "auto"); } } }, 500); } document.addEventListener('keyup', checkIfInputsExist); console.log(123213213);