function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}
//-->

function isEmpty( str){
    strRE = new RegExp( );
    strRE.compile( '^[\s ]*$', 'gi' );
    return strRE.test( str.value );
}

function notValidEmail( str ){
    mailRE = new RegExp( );
    mailRE.compile( '^[\._a-z0-9-]+@[\.a-z0-9-]+[\.]{1}[a-z]{2,4}$', 'gi' );
    return !(mailRE.test( str.value ));
}

function notChecked( box ){
    if( box.checked ){
        return false;
    }
    else{
        return true;
    }
}

//it accepts "form" as parameter
function checkForm( form ){

    //lets check if Name text field is empty. This field has name "name".
    if( isEmpty( form.name ) ){
        alert( 'Name is required field!' );
        return false;
    }

    //now let's check if email is correct. This field name is "email"
    if( notValidEmail( form.email ) ){
        alert( 'Dont forget your Email Address!' );
        return false;
    }

    //now let's check if checkbox is checked. This field name is "subscribe"
    if( notChecked( form.subscribe ) ){
        alert( 'Subscribe box is required field!' );
        return false;
    }

	alert('Form is okay!!!');
    return false;
}