function $(id)
{
	return document.getElementById(id);
}
function ch1()
{
    		$("d1").style.display="";
			$("d2").style.display="none";
			$("s1").className="top_companyfile1";
			$("s2").className="top_companyfile_change"	;		
}
function ch2()
{
    		$("d1").style.display="none";
			$("d2").style.display="";		     		
			$("s1").className="top_companyfile_change";
			$("s2").className="top_companyfile1";
}

function ch3()
{
    		$("d3").style.display="";
			$("d4").style.display="none";
			$("d5").style.display="none";
			$("s3").className="top_companyfile1";
			$("s4").className="top_companyfile_change";
			$("s5").className="top_companyfile_change"	;
}
function ch4()
{
    		$("d3").style.display="none";
			$("d5").style.display="none";
			$("d4").style.display="";		     		
			$("s3").className="top_companyfile_change";
			$("s5").className="top_companyfile_change";
			$("s4").className="top_companyfile1";
}
function ch5()
{
    		$("d3").style.display="none";
			$("d4").style.display="none";
			$("d5").style.display="";		     		
			$("s3").className="top_companyfile_change";
			$("s4").className="top_companyfile_change";
			$("s5").className="top_companyfile1";
}
/*
 * check the tell number
 */
function isTel(str)
{
  
   
   if(str.length<7 || str.length>18)
   {
		return false;
   }
   else
   {
	   var reg=/^([0-9]|[\-][\(][\)])+$/g ;
	   return reg.test(str);
   }
}
/*
 * check the email
 */
function isEmail(str)
{
    var reg = /^([a-zA-Z0-9]){1}([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+((\.[a-zA-Z0-9_-]{2,3}){1,2})$/;
    return reg.test(str);
}
function check_form(a)
{
	if(a.name.value=='')
	{
		alert('Please enter your name!');
		return false;
	}
	
	if(a.email.value=='')
	{
		alert('Please enter your email!');
		return false;
	}
	else if (!isEmail(a.email.value))
	{
		alert('Please enter a valid email address!');
		return false;
	}

	if(a.tell.value=='')
	{
		alert('Please enter your Call number!');
		return false;
	}
	else if (!isTel(a.tell.value))
	{
		alert('Please enter a valid Call number!');
		return false;
	}


	if(a.comment.value=='')
	{
		alert('Please enter your comment!');
		return false;
	}
}

function check_form_contactus(a)
{
	if(a.name.value=='')
	{
		alert('Please enter your name!');
		return false;
	}
	
	if(a.email.value=='')
	{
		alert('Please enter your email!');
		return false;
	}
	else if (!isEmail(a.email.value))
	{
		alert('Please enter a valid email address!');
		return false;
	}

	if(a.tell.value=='')
	{
		alert('Please enter your Call number!');
		return false;
	}
	else if (!isTel(a.tell.value))
	{
		alert('please enter a valid Call number!');
		return false;
	}
	if(a.company.value=='')
	{
		alert('please enter your company!');
		return false;
	}
	if(a.country.value=='')
	{
		alert('Please enter your country!');
		return false;
	}
}

function check_requirement(a)
{
	if(a.name.value=='')
	{
		alert('Please enter your name !');
		return false;
	}
	
	if(a.address.value=='')
	{
		alert('Please enter your email!');
		return false;
	}
	else if (!isEmail(a.address.value))
	{
		alert('Please enter a valid email address!');
		return false;
	}

	if(a.tel.value=='')
	{
		alert('Please enter your Call number !');
		return false;
	}
	else if (!isTel(a.tel.value))
	{
		alert('please enter a valid Call number!');
		return false;
	}
	if(a.code.value=='')
	{
		alert('Please enter the word verification!');
		return false;
	}

}

function check_pilot(a)
{
	if(a.name.value=='')
	{
		alert('Please enter your name!');
		return false;
	}
	
	if(a.email.value=='')
	{
		alert('Please enter your email!');
		return false;
	}
	else if (!isEmail(a.email.value))
	{
		alert('Please enter a valid email address!');
		return false;
	}

	if(a.tel.value=='')
	{
		alert('Please enter your Call number!');
		return false;
	}
	else if (!isTel(a.tel.value))
	{
		alert('please enter a valid Call number!');
		return false;
	}
	if(a.company.value=='')
	{
		alert('Please enter your company!');
		return false;
	}
	if(a.code.value=='')
	{
		alert('Please enter the word verification!');
		return false;
	}

}

function check_evelution(a)
{
	if(a.name.value=='')
	{
		alert('Please enter your name!');
		return false;
	}
	
	if(a.email.value=='')
	{
		alert('Please enter your email!');
		return false;
	}
	else if (!isEmail(a.email.value))
	{
		alert('Please enter a valid email address!');
		return false;
	}

	if(a.tel.value=='')
	{
		alert('Please enter your Call number!');
		return false;
	}
	else if (!isTel(a.tel.value))
	{
		alert('please enter a valid Call number!');
		return false;
	}
	if(a.job_title.value=='')
	{
		alert('Please enter the job title!');
		return false;
	}
	if(a.file_name.value!='')
	{
		var s = a.file_name.value;
		s = s.substr(s.lastIndexOf(".")+1);
		
		if(s=='exe')
		{

			alert("this type of file can't uploade!")
			return false;
		}
	}
	if(a.code.value=='')
	{
		alert('Please enter the word verification!');
		return false;
	}
}