One word JavaScript form verification Code _javascript tips

The form's client JavaScript validation has a variety of ways to write, log in as a onsubmit event for the form, or submit a function by pressing the button. For small forms (forms with only one or two form fields), there is no need to specifically use JavaScript to write a validation function, just add in the onsubmit event of the form:

Copy Code code as follows:

onsubmit= "Return domainname.value=="? (Alert (' Please enter search content '), false): true; "

This is only a word, the implementation of the validation of successful submission, when the failure to give a hint of the function. Where DomainName is the name of the form field to be validated. Of course, when the form field is more, the verification process is more complex, this is not appropriate to write.