Javascript change input value

Question

In my website I have a box that is not displayed. When the user types his username and password, if they are correct, the box must be displayed. Here you see the HTML code:

<div id="mainbox" style="display: none;">
    <p class="classm">Test.</p>
</div>    
<input type="text" id="user"/>
<br />
<input type="text" id="password" value="a"/>
<br />
<input type="button" value="Log in" onclick="login();">

And here the javascript function:

function login() {
    var a = document.getElementById('password').value;
    var b = document.getElementById('user').value;
    if ((a == 'qwe') && (b == 'rty')) { //the problem is not here
     document.getElementById('password').style.display="none";
    }
    else
    {
     alert('You are not logged in.');  
    }
}

When I click the button Log in looks like the function login(); is not called because anything happen. Do you know why?

Are you sure you are typing the right letters in the right box? The first box needs to be 'rty' and the second 'qwe'. — putvande
– putvande, Commented Aug 31, 2013 at 10:56

Praveen · Accepted Answer · 2013-08-31 10:59:58Z

4

if (a == 'qwe') && (b == 'rty') //Wrong

Enclose the condition like if( condition )

 if ((a == 'qwe') && (b == 'rty') ) //Corect

As @Frédéric Hamidi suggested, there is no need of inner parentheses.

Simple like this

if (a == 'qwe' && b == 'rty' )

Demo here

edited Aug 31, 2013 at 10:59

answered Aug 31, 2013 at 10:50

Praveen

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3 Comments

Frédéric Hamidi Over a year ago

Nitpicking: == has more precedence than &&, so the inner parentheses are not required.

Sergio Over a year ago

@AlbertoRossi, I think you have a & b mixed, a should be user, and b pass, or? I added a demo to this answer. Check it out.

Praveen Over a year ago

@FrédéricHamidi You're right, I have included in it in my answer. Thanks for the pointers.

Tushar Gupta - curioustushar · Accepted Answer · 2013-08-31 10:52:14Z

2

use proper if

if (a == 'qwe' && b == 'rty' )

fiddle

answered Aug 31, 2013 at 10:52

Tushar Gupta - curioustushar

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