What are a fixed-width table and its advantages in JavaScript?

Fixed width tables are rendered by the browser based on the widths of the columns in the first row, in JavaScript resulting in a faster display in case of large tables. Use the CSS style table-layout:fixed to specify a fixed width table.
If the table is not specified to be of fixed width in JavaScript, the browser has to wait till all data is downloaded and then infer the best width for each of the columns. This process can be very slow for large tables.

How to have the status line update when the mouse goes over a link ?

onmouseover="window.status='Hi There!';return true"
onmouseout="window.status='';return true"

need to set the cursor at the end of text in textbox

function setSelectionRange(input, selectionStart, selectionEnd) {
if (input.setSelectionRange) {
input.focus();
input.setSelectionRange(selectionStart, selectionEnd);
}
else if (input.createTextRange) {
var range = input.createTextRange();
range.collapse(true);
range.moveEnd('character', selectionEnd);
range.moveStart('character', selectionStart);
range.select();
}
}
function setCaretToEnd (input) {
setSelectionRange(input, input.value.length, input.value.length);
}

Detect special characters in text box. Or any character you subsitute for the special characters.

var iChars = "!@#$%^&*()+=-[]\\\';,./{}|\":<>?";
for (var i = 0; i < document.formname.fieldname.value.length; i++) {
if (iChars.indexOf(document.formname.fieldname.value.charAt(i)) != -1) {
alert ("The box has special characters. \nThese are not allowed.\n");
return false;
}
}

Remove special characters from a string.

Remove special characters from a string.

function clearText() {
document.formname.fieldname.value=filterNum(document.formname.fieldname.value)

function filterNum(str) {
re = /\$|,|@|#|~|`|\%|\*|\^|\&|\(|\)|\+|\=|\[|\-|\_|\]|\[|\}|\{|\;|\:|\'|\"|\<|\>|\?|\||\\|\!|\$|\./g;
// remove special characters like "$" and "," etc...
return str.replace(re, "");
}
}

Scan values in a field and if they are all letters then alert. The second block of code does the same but for numbers

//alert on finding all letters
var noalpha = /^[a-zA-Z]*$/;
if (noalpha.test(document.formname.fieldname.value)) {
alert("Please enter at least one number in the \"username\" field.");
return false;
}

//alert on finding all numbers
var nonums = /^[0-9]*$/;
if (nonums.test(document.formname.fieldname.value)) {
alert("Please enter at least one letter in the \"username\" field.");
return false;
}

Check drop down has been selected. Set drop down's value to Not_Selected for this to work.

if (document.formname.fieldname.value == 'Not_Selected')
{
alert("Please provide us with a selection.\n");
return false;
}