var myreg1=/([a-z0-9A-Z]+[-|\.]?)+[a-z0-9A-Z]@([a-z0-9A-Z]+(-[a-z0-9A-Z]+)?\.)+[a-zA-Z]{2,}$/

 function checkform()
 {
   
    if(document.reg.sel1.value==""||document.reg.sel1.value==null)
	{
	   alert("The event to fill!");
	   document.reg.sel1.focus();
	   return false;
	   
	}
   if(document.reg.UserName.value==""||document.reg.UserName.value==null)
	{
	   alert("Names to fill!");
	   document.reg.UserName.focus();
	   return false;
	   
	}
	else if(document.reg.UserName.value.length<3)
	{
	   alert("Name at least 3 characters!");
	   document.reg.UserName.focus();
	   return false;
	   
	}
	
	else if(document.reg.company_c.value==""&&document.reg.company_E.value=="")
	{
	   alert("Company name(Chinese) or company name(English) to fill in!");
	   document.reg.company_c.focus();
	   return false;
	   
	}
	else if(document.reg.post.value=="")
	{
	   alert("Zip to fill!");
	   document.reg.post.focus();
	   return false;
	   
	}
		
	else if(document.reg.tel1.value==""||document.reg.tel3.value=="")
	{
	   alert("Your telephone should be completed!");
	   
	   return false;
	   
	}
	else if(document.reg.fax1.value==""||document.reg.fax3.value=="")
	{
	   alert("Fax to fill out a complete!");
	 
	   return false;
	   
	}
	
	else if(document.reg.email.value=="")
	{
	   alert("E-mail to fill out!");
	   document.reg.email.focus();
	   return false;
	   
	}
	else if(!myreg1.test(document.reg.email.value))
	{
	    alert("Email format is incorrect!");
	   document.reg.email.focus();
	   return false;
	   
	}
	
	
	
	return true;
 }
 
 
 function mykeydown(){
   if(event.keyCode==116){
     window.event.keyCode=0;
     return false;
   }
  
 }
 
 document.onkeydown=mykeydown;