Uncaught TypeError : Cannot Read property value of null [duplicate]

Answer 1

Move your script to the end of the body or wrap it in a DOM ready function. Your getElementById is executing before the page is rendered, thus throwing a null error.

Example:

$(document).ready(function(){
    var usr = document.getElementById("textbox1").value;//error is over this line.
    if(usr.length<=6){
        $("#press").click(function(){
            $("#warning").toggle();
        });
    }
 });