thank you! it worked like a charm. I have one more of the same issue and I am trying to see if it wont run for the same problem or what, but I'm stumped on this and it's copied straight from the book I am using.
<title>Calculating the area of a circle</title>
//program that calculates and prints the area
//of a circle and half circle
var pi = 3.14159; // mathematical value of PI
//Ask the user for the size of the circle
var radius = promt("What is the radius of the circle?");
//calculate the area of the whole circle
var area = pi*radius*radius;
//Making these parts of the message to user strings
//both demonstrates strings and makes the alert fit
//more cleanly on a single line.
var message1 = " The area of a circle with the radius of ";
var message2 = " is ";
alert(message1 + radius + message2 + area);
alert("The area of a half circle is " + area/2);