How can we do validation without submitting any form.

Actually I have 2 forms. one is Form1.php and second is result1.php. Form1.php is having 3 fields which are username, age and occupation. When I am validating this form it alert the message to fill the desired field and goes to result1.php. But I want that when all the fields are correctly filled then only the form1.php will submit and show the result in result1.php. How can i do this?

Thanks.

for every form you have to make separate java script function.on form submission call that function . In that function you have to write logic to validate that form like
name if(document.formname.fieldname.value==''){
alert("enter name");
}