JavaScript Validation functions

Below javascript functions will definitely useful to validate html elements in our web page.

/* return a string where left & right spaces are removed */
function trim(s){ return s.replace(/^\s*|\s*$/g,”"); }

/* true if ’s’ is a 4 digit year, false if not */
function isYear(s){ return (s.search(/^\d{4}$/) == -1) ? false:true; }

/* true if ’s’ is empty, false if not */
function isEmpty(s){ return (trim(s).length > 0) ? false:true; }

/* true if ’s’ is a valid email address, false if not */
function isEmail(s){ return (trim(s).search(/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/) == -1) ? false:true; }

/* true if ’s’ is in date format, false if not! ex: 01-01-2004, 1-1-2004, 01-1-2004 - all valid format */
function isDateFormat(s){ return (trim(s).search(/^(\d{1,2})(-)(\d{1,2})(-)(\d{4}$)/) == -1) ? false:true; }

/* true if ’s’ is a valid date value, false if not */
function isDateValid (s){
var ar = s.split(”-”);
var m = parseInt(ar[0],10) - 1, d = parseInt(ar[1],10), y = parseInt(ar[2],10);
var dD = new Date(y,m,d);
return ((d==dD.getDate()) && (m==dD.getMonth()) && (y==dD.getFullYear()));
}

/* true if ’s’ is a number (w/ or w/out unary +/-, w/ or w/out a dot), false if not! ex: 100, 10., 100.99 */
function isNumber(s){ return (trim(s).search(/^([+-]{0,1}\d{1,}([.]{0,1}\d*)*)$/) == -1) ? false:true; }

/* true if ’s’ is a whole number (w/ or w/out unary +/- symbol), false if not */
function isWholeNumber(s){ return (trim(s).search(/^([+-](\d+)|(\d+))$/) == -1) ? false:true; }

/* true if ’s’ is valid password (only all of these [0-9,a-z,A-Z,_-]), false if not. */
function isPasswordCombinationValid(s){
if(s.search(/^([-_a-z\d]+)$/i) == -1) return false; /* only these [0-9,a-z,A-Z,_-] */
if(s.search(/[a-z]/i) == -1) return false; /* letters */
if(s.search(/\d/) == -1) return false; /* digits */
if(s.search(/[-_]/) == -1) return false; /* _ & - */
return true;
}

/* true if ’s’ is a valid user id (only any combination of these [0-9,a-z,A-Z,_]), false if not */
function isUserIdCombinationValid(s){ return (s.search(/^([_a-z\d]+)$/i) == -1) ? false:true; }

/* true if ’s’ is in the format (99)999-999 */
function isTel_Fax(s){ return (s.search(/^([(])(\d{1,2})([)])(\d{3,3})(-)(\d{4,4})/) == -1) ? false:true; }

/* true if ’s’ is a valid program code (only any combination of these [0-9,a-z,A-Z,_]), false if not */
function isProgCodeCombinationValid(s){ return (s.search(/^([_a-z\d]+)$/i) == -1) ? false:true; }