05. Form validator

jQuery

function result() {

            let company = false

            $('#company').click(function() {
                if( $(this).is(':checked')) {
                   $('#companyInfo').css('display', 'block')
                    company=true
                } else {
                    $('#companyInfo').css('display', 'none')
                    company=false
                }
            })

            let submit = $('#submit')
            submit.on('click', function (event) {

                let user =false
                let pass = false
                let email = false
                let comp = false

                let userNameField = $('#username')
                let userNameValue = userNameField.val()
                let userNameRegex = /^[a-zA-Z0-9]{3,20}$/
                let test = userNameRegex.test(userNameValue)
                if(test){
                    $(userNameField).css('border','none')
                    user = true
                } else{
                    $(userNameField).css('border','2px inset')
                    $(userNameField).css('border-color','red')
                    user = false
                }

                let passField = $('#password')
                let passValue = passField.val()
                let passRegex = /^[a-zA-Z0-9_]{5,15}$/
                let test1 = passRegex.test(passValue)
                let confPassField = $('#confirm-password')
                let confPassValue = confPassField.val()
                if(test1 && passValue == confPassValue){
                    $(passField).css('border','none')
                    $(confPassField).css('border','none')
                    pass = true
                } else{
                    $(passField).css('border','2px inset')
                    $(passField).css('border-color','red')
                    $(confPassField).css('border','2px inset')
                    $(confPassField).css('border-color','red')
                    pass = false
                }

                let emailField = $('#email')
                let emailValue = emailField.val()
                let emailRegex = /@[\s\S]+?\./
                let test2 =emailRegex.test(emailValue)
                if(test2){
                    $(emailField).css('border','none')
                    email = true
                } else{
                    $(emailField).css('border','2px inset')
                    $(emailField).css('border-color','red')
                    email = false
                }

                if(company){
                    let companyField = $('#companyNumber')
                    let companyValue = Number(companyField.val())
                    if(companyValue>= 1000 && companyValue <= 9999){
                        $(companyField).css('border','none')
                        comp = true
                    } else{
                        $(companyField).css('border','2px inset')
                        $(companyField).css('border-color','red')
                        comp = false
                    }
                    if(user && pass && email && comp){
                        $('#valid').css('display','block')
                    } else{
                        $('#valid').css('display','none')
                    }
                } else{
                    if(user && pass && email){
                        $('#valid').css('display','block')
                    } else{
                        $('#valid').css('display','none')
                    }
                }
                event.preventDefault()
            })
    }