how to validate a form using JavaScript? [closed]

Answer 1

add an OnClick="function_name();" in the html of your submit button,

and in the declaration of the function do this

function function_name(){
     var str = document.getElement("your_text_field_id");
     if (str=="") {
       alert("Please type some text first");
       return false
     } else { 
       alert("Thanks");  //optional
       return true;
     }
}