JavaScript Examples Bible - UserWorks Technologies

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JavaScript Examples Bible: The Essential Companion to JavaScript Bible
Event handlers
onClick
NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5
Compatibility ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
Example
Listing 24-1 demonstrates not only the onClick event handler of a button but
also how you may need to extract a particular button’s name or value properties
from a general-purpose function that services multiple buttons. In this case, each
button passes its own object as a parameter to the displayTeam() function. The
function then displays the results in an alert dialog box. A real-world application
would probably use a more complex if...else decision tree to perform more
sophisticated actions based on the button clicked (or use a switch construction on
the btn.value expression for NN4+ and IE4+).
Listing 24-1: Three Buttons Sharing One Function
Button Click
function displayTeam(btn) {
if (btn.value == “Abbott”) {alert(“Abbott & Costello”)}
if (btn.value == “Rowan”) {alert(“Rowan & Martin”)}
if (btn.value == “Martin”) {alert(“Martin & Lewis”)}
}
Click on your favorite half of a popular comedy team:
document.formObject.buttonObject.onClick