function my_select(type) {
    frm = document.forms.studentlist;
    ele = frm["id[]"];
    len = ele.length;
    for (i = 0; i < len; i++)
    ele[i].checked = type;
}
 
 
function changePwdCheck() {
    if (document.getElementById('new_password').value == document.getElementById('new_password_confirm').value ) {
        if (document.getElementById('new_password').value.length < 6 ) {
            alert('Make your new password longer!');
            return false;
        } else {
            return true;
        }
    } else {
        alert('New password fields don\'t match!');
        return false;
    } // if else
}
 
function checkentry(form) {
    var mymonth = form.month.value;
    var myhours = form.duration_hours.value;
    var myminutes = form.duration_minutes.value;
    var myday = form.day.value;
    var myyear = form.year.value;
    var myactivity = form.type.value.length;
    var mydetails = form.summary.value.length;
    if (myhours == 0 && myminutes == 0) {
        alert("You must have done this activity for at least five minutes!");
        return false;
    }
     
    switch(mymonth) {
        case "1":
        case "3":
        case "5":
        case "7":
        case "8":
        case "10":
        case "12":
        break;
        case "2":
        if ((myday > 29 && myyear/4 == parseInt(myyear/4) && myyear/400 != parseInt(myyear/400)) || (myday > 28 && myyear/4 != parseInt(myyear/4))) {
            alert("The date is invalid");
            return false;
        }
        break;
        default:
        if (myday > 30) {
            alert("The date is invalid");
            return false;
        }
        break;
    }
    if (myactivity == 0 || mydetails == 0) {
        alert("Fill in both text fields!");
        return false;
    }
     
}
 
function check(form) {
    var grade = form.grade.value;
    var first_name = form.first_name.value;
    var last_name = form.last_name.value;
    var courses = form.courses.value;
    var times = form.times.value;
    var agree = form.agree.checked;
    if (grade != 9 && grade != 10 && grade != 11 && grade != 12) {
        alert('Enter a valid grade!');
        return false;
    }
    else if(first_name.length == 0 || last_name.length == 0) {
        alert('The student\'s name is missing important information!');
        return false;
    }
    else if(times.length == 0 || courses.length == 0) {
        alert('Please enter your tutoring requests');
        return false;
    }
    else if(!agree) {
        alert('You must agree with our statement');
        return false;
    } else {
        return true;
    }
}
 
function checkAddStudent(form) {
    var grade = form.grade.value;
    var first_name = form.first_name.value;
    var last_name = form.last_name.value;
    if (grade != 9 && grade != 10 && grade != 11 && grade != 12) {
        alert('Enter a valid grade!');
        return false;
    }
    else if(!(first_name) || !(last_name)) {
        alert('The student\'s name is missing important information!');
        return false;
    }
    else
        return true;
}
 
function popUp(URL) {
    day = new Date();
    id = day.getTime();
    eval("page" + id + " = window.open(URL, '" + id + "', '');");
}
 
function endAddStudent() {
    window.opener.location.reload();
    window.close();
}

function enterEdit( id ) {
    document.getElementById( 'view' + id ).style.display = 'none';
    document.getElementById( 'edit' + id ).style.display = 'block';
}


function exitEdit( id ) {
    document.getElementById( 'view' + id ).style.display = 'block';
    document.getElementById( 'edit' + id ).style.display = 'none';
}