Javascript Form Verification _ javascript skills

JavaScript is used to verify the data entered in the html form before the data is transmitted to the service. It is necessary to use javascript to verify the information entered by the user, the following small series will help you sort out some commonly used javascript form verification. For more information, see Typical form data verified by JavaScript includes the following types:

1. Have you entered required items in the form?

2. Is the email address entered by the user valid?

3. Have you entered a valid date?

4. Have you entered text in the numeric field?

The user name and password verification code is as follows:

 Untitled documentScript function validateForm () {var username = document. forms ["myForm"] ["username"]. value; var password = document. forms ["myForm"] ["password"]. value; alert (username + "" + password);} script

Required (or required) Project Verification:

The following function is used to check whether the user has entered a required (or required) project in the form. If required or required, the warning box is displayed, and the return value of the function is false. Otherwise, the return value of the function is true (meaning there is no data problem ):

function validate_required(field,alerttxt){with (field){if (value==null||value=="") {alert(alerttxt);return false}else {return true}}}

The following code is used together with the HTML form: