First, verify or correct some browser settings...

Internet Explorer

• In Internet Explorer, click on the Tools menu, and select Internet Options.
• In Internet Options, click the Security tab.
• There are four icons that represent security zones.
• Set each zone, one by one, to Default (button towards the bottom).
• Click Apply to apply the new settings, then OK to close the options.

Mozilla / Netscape

• In Netscape or Mozilla, click on the Edit menu, and select Preferences.
• In Preferences, double-click Advanced to select and expand that section.
• Click on Scripts & Plugins (on the left, under the Advanced section).
• Check Enable JavaScript for Navigator -- check all the boxes below too.
• Click OK to close the preferences.