Cross-Browser Scripting

The introduction of Netscape 6 has worsen the browser-independent scripting situation, at least for a short time. No longer do you have to deal with only two browsers - there are now three major browsers to support. One good old way is to use if statements. You want to make your script as generic as possible, and use if clauses as late as possible. The following script uses this technique. The switchEntries() function is a common event handler for all browsers. The content of switchEntries() is an if statement that executes a different statement for every browser:

<FORM NAME="election">
<SELECT NAME="presidents">
<OPTION NAME="leaving">Al Gore
<OPTION SELECTED>George W. Bush
</SELECT>
<INPUT TYPE="button" VALUE="Switch first option"
  onclick="switchEntries()">
</FORM>
<SCRIPT LANGUAGE="JavaScript">
<!--
function switchEntries() {
  if (document.all) {
    document.election.presidents.item(0).text = 'Bill Clinton';
  }
  else if (document.layers) {
         document.election.presidents[0].text = 'Bill Clinton';
       }
       else if (document.getElementById) {
              document.election.leaving.text = 'Bill Clinton';
            }
}
// -->
</SCRIPT>

Click the button below to see how the first option changes on the fly:

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