JavaScript Very Frequently Asked Questions FAQ

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• FAQ 1 How do you check if a date is valid?
• FAQ 6 How do you display the .00, or in the case of 50 cents display .50 instead of .5?
• FAQ 13 How can I password protect a page?
• FAQ 19 How do I read data from an input file?
• FAQ 25 How can you find information about the contents of another frame?
• FAQ 42 How do I detect the version of JavaScript the users browser supports?
• FAQ 43 How do I detect the browser the user is using?
• FAQ 80 How can I pass checkbox or radio value to another page?
• FAQ 101 How can I read and write to a text file?
• FAQ 106 Looking for a good simple JavaScript counter?
• FAQ 109 I am thinking of learning JavaScript as it would appear to be extremely useful and effective. However, I have no previous programming experience other than HTML. Do you think this is feasible or is it too ambitious?
• FAQ 131 How do I add form elements together, I have tried many different ways but I always either get NaN or a concenated string (ie 15 + 16 + 1 + 52 = 1615152 != 84)?
• FAQ 134 Is it possible to send an email from a JavaScript?
• FAQ 150 How do I change text within table cells?
• FAQ 210 I keep receiving function undefined in the following script, why?
• FAQ 236 How can I show a different image each day?
• FAQ 255 How can I combine the previous scripts so that a layer in either Netscape 4 or Explorer 4 is always positioned in the same location on the screen regardless of where in the document the user is currently located?
• FAQ 272 When a page is reloaded how can it check that any window it previously opened is not still open before attempting to open it again?
• FAQ 276 How do I call two functions from the body tags onLoad event handler?
• FAQ 287 How do I display a random banner image?
• FAQ 311 How do I disable the "Back" button of a browser?
• FAQ 320 Where can I get information about image rollover/mouseovers/highlighting/swapping?
• FAQ 325 How can I make a script that will automatically reply an e-mail?
• FAQ 438 What's the difference between Java and JavaScript and why should I prevent my browser from executing JavaScript?
• FAQ 442 How can I hide the JavaScript source code from "view source" function of the browser?
• FAQ 443 Can you use JavaScript to send emails?
• FAQ 452 Is there a way to close a window without that confirm message?
• FAQ 455 How do you hide the real address of a page?
• FAQ 477 Is JavaScript the same as Java?
• FAQ 478 What is JavaScript?
• FAQ 479 How do I detect the resolution of the visitor's monitor and redirect him to another page?
• FAQ 480 How do I pass the value of a text field when the submit button is pressed onto the next page?
• FAQ 481 Can I print the current page on both Netscape Navigator and Internet Explorer?
• FAQ 482 Is there any way to detect plugins?
• FAQ 495 Is JavaScript used only to make web pages better?
• FAQ 496 Will learning JavaScript make learning Java any easier?
• FAQ 498 Do you know of anyway to retrieve data from a .txt file located on the server?
• FAQ 558 How can I avoid people bookmarking pages and returning later without logging onto my site?
• FAQ 563 Can JavaScript code situated on the server write to a file on that server?
• FAQ 564 Why is JavaScript not a progamming language but a scripting language and what is a scripting language?
• FAQ 581 How can I highlight normal text using onMouseover?
• FAQ 609 How can I use entities with Microsoft Internet Explorer?
• FAQ 629 How can I round a decimal number to a whole number (ie: 1.52=2)?
• FAQ 634 How do I get the *.js files to not display their code in Netscape?
• FAQ 635 How can I scramble my JavaScript source code so that it is not easily copied?
• FAQ 647 When submitting a form, how do I load a thank you page when the user presses the submit button?
• FAQ 649 Can you detect if JavaScript is enabled on the users browser?
• FAQ 660 How can I swap an image using onMouseOver in an image map?
• FAQ 669 How can you change the location of two frames by clicking a text link?
• FAQ 945 Is there any way to close the browser window without the confirmation dialog that pops up when using "window.close()"?
• FAQ 1542 How can I print a page without the print dialogue box?
• FAQ 1551 How do I make a box with a list of hyperlinks appear when the mouse cursor hovers over text, as seen at www.microsoft.com?
• FAQ 1572 Where can I find FAQs for server-side javascript?
• FAQ 1578 How can I detect, that the user has closed the window (including the use of alt-F4)?
• FAQ 1595 How can I disable the "View Source" menu item?
• FAQ 1647 How do I force Internet Explorer to print an HTML page as landscape rather than portrait?
• FAQ 1685 How do I get the IP address of the visitor?
• FAQ 1732 How can I display an absolutely positioned layer of content over form fields so that the form fields do not show through the layer?

©2013 Martin Webb