Menu Selection Populates Text Field

I have the following code I picked up which tries to fill in a text field with data depending on a user's menu item selection. I place this code in the header:

Code:
var colors = new Array();
colors["apple"] = "red";
colors["grape"] = "purple";
colors["milk"] = "white";
colors["cheese"] = "yellow";
colors["chicken"] = "white";
colors["beef"] = "red"; .....

var groups = new Array();
groups["apple"] = "fruit";
groups["grape"] = "fruit";
groups["milk"] = "diary";
groups["cheese"] = "diary";
groups["chicken"] = "meat";
groups["beef"] = "meat";

function printColorAndGroup(){
var value = document.getElementByName('food').options[document.getElementByName('food').selectedIndex].value;
document.getElementByName('food_group').value = groups[text];
document.getElementByName('food_color').value = colors[text];
}

I then use the following html in the body:
Code:
Food:
<select name="food" onchange="printColorAndGroup()">
<option>apple</option>
<option>grape</option>
<option>milk</option>
<option>cheese</option>
<option>chicken</option>
<option>beef</option>
</select>

Group:
<input type="text" name="food_group">
Color:
<input type="text" name="food_color">
But when I run this nothing happens...
Here's the page [URL]. None of the code above is colored... looks like I'm using the wrong tags here. Which tags should I use to post this stuff correctly?