size1 = "Blank";

var hint = 'You have to determine the velocity and mass of the companion star, and the inclination angle of the system to use the formula. Don\'t forget to check your units!!';
var blank = 'You need to enter a value in the blank space!'

function checkme() {
    size1 = document.CygX1Mass.answer.value - 0;

    RightOnFile = './binary-correct.html';
    CloseFile = './binary-close.html';
    WayWrongFile = './binary-wrong.html';
    ReturnFile = './binary-formula.html#return';

    if (!size1) {size1 = "Blank";
    window.alert(blank);
    location = returnFile;
}


loGood = 8;
hiGood = 17;
loClose = 6;
hiClose = 19;
 
if ((size1 >= loGood) && (size1 <= hiGood)){
    location = RightOnFile
}

else if ((size1 <= loClose) || (size1 >= hiClose)) {
    location = WayWrongFile

} else {
    location = CloseFile
}
}