function checkForm ()
{
    valid = true;
    if ( document.contactForm.f1.value == "" )
    {

        valid = false;
    }

	apos= document.contactForm.f2.value.indexOf("@")
	dotpos= document.contactForm.f2.value.lastIndexOf(".")
	    if ( document.contactForm.f2.value == "" || apos<1 || dotpos-apos<2)
    {

        valid = false;
    }

if (valid == false) {
tb_show("<img src='images/shared/alert.gif' alt='Error'/>","#TB_inline?height=40&amp;width=300&amp;inlineId=hiddenModalContentForm&amp;modal=false");
  }
    return valid;
}