function validateForm() {
    var letters = /^[a-zA-Z\s]*$/;
    var numbers = /^[-+]?[0-9]+$/;
    let pname = document.forms["myForm"]["pname"].value;
    let pid = document.forms["myForm"]["pid"].value;
    let cusname = document.forms["myForm"]["cusname"].value;
    let cusphone = document.forms["myForm"]["cusphone"].value;
    let cuscity = document.forms["myForm"]["cuscity"].value;
    let cuscon = document.forms["myForm"]["cuscon"].value;
    let cuszip = document.forms["myForm"]["cuszip"].value;
    if (!pname.match(letters)) {
        alert("Product name: Please input alphabet characters only");
        return false;
    }
    else if (!pid.match(numbers)) {
        alert("Product id: Please input numbers only");
        return false;
    }
    else if (!cusname.match(letters)) {
        alert("Customer Name : Please input alphabet characters only");
        return false;
    }
    else if (!cusphone.match(numbers)) {
        alert("Phone nnumber : Please input numbers only");
        return false;
    }
    else if (!cuscity.match(letters)) {
        alert("City : Please input alphabet characters only");
        return false;
    }
    else if (!cuscon.match(letters)) {
        alert("Country : Please input alphabet characters only");
        return false;
    }
    else if (!cuszip.match(numbers)) {
        alert("Zip Code : Please input numbers only");
        return false;
    }

    sessionStorage.setItem("pname", pname);
    sessionStorage.setItem("pid", pid);
    sessionStorage.setItem("cusname", cusname);
    sessionStorage.setItem("cusphone", cusphone);
    sessionStorage.setItem("cuscity", cuscity);
    sessionStorage.setItem("cuscon", cuscon);
    sessionStorage.setItem("cuszip", cuszip);
    return true;
}

function show_info_table() {
    document.getElementById("pname").innerHTML = sessionStorage.getItem("pname");
    document.getElementById("pid").innerHTML = sessionStorage.getItem("pid");
    document.getElementById("cusname").innerHTML = sessionStorage.getItem("cusname");
    document.getElementById("cuscity").innerHTML = sessionStorage.getItem("cuscity");
    document.getElementById("cuscon").innerHTML = sessionStorage.getItem("cuscon");
    document.getElementById("cuszip").innerHTML = sessionStorage.getItem("cuszip");
}