isSet javascript variable

by Ruben Ruiz Perez

HTML

x = <input type="text" id="x" value="   " />   &nbsp; &lt; spaces or empty string ""<br /><br />
<input class="btn btn-default" type="button" id="btn" value="check"> <br /><br />
    
    <div id="result"></div>

JavaScript

function isSet(variable)
	{
		result = true;
        
        if(typeof(variable) == 'string')
            variable = variable.trim();
        
		if(
			typeof(variable) == 'undefined' ||
			variable == 'undefined' ||
			variable == undefined || //NO QUOTE
			variable == '' ||
			variable == null
		)
			result = false;

		return result;
	}

$(document).ready( function (){

    $('#btn').click(function()
    {
        var x = $('#x').val();        
        $('#result').html('isSet(x) = '+isSet(x));
    });
   
});