Validating all text fields.

I needed to validate all the text fields on the page and restrict the user from entering scripts into text fields and text areas. Following is the solution (Using a simple regular expression).

This function should be called on submit of the form.

function ValidateAllFieldsForScripting() {

//Checking all text boxes

var f = document.getElementsByTagName(‘input’);

var isInputValid = true;

for (var i = 0; i < f.length; i++) {

if (f[i].getAttribute(‘type’) == ‘text’) {

if (checkScriptInput(f[i]) == false) {

isInputValid = false;

}

}

}

// Checking all text areas.

f = document.getElementsByTagName(‘textarea’);

for (var i = 0; i < f.length; i++) {

if (checkScriptInput(f[i]) == false) {

isInputValid = false;

}

}

if (isInputValid)

return true;

else {

ShowInvalidInputDiv();

return false;

}

}

// This function checks the text field for script input.

function checkScriptInput(obj) {

var legalChars = /[\<\>]/;

if (legalChars.test(obj.value)) {

obj.style.background = ‘#FFF1F5′;

return false;

} else {

return true;

}

}

/// Function for displaying error message.

function ShowInvalidInputDiv() {

// Here you should write the code for displaying some error message to the user.

}