function validate()  //form validation function
{
var emailExp = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*\.(\w{2}|(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum))/;
var numericExpression = /^[0-9]+$/; 
var alphaExp = /^[a-zA-Z]+$/;


       if(document.form1.tb_first_name.value.match(numericExpression) || (document.form1.tb_first_name.value == ""))
       {
    	alert("Please enter only letters for your first name.");
		document.form1.tb_first_name.focus();
		document.form1.tb_first_name.value = "";
        return false;
     }
     if(document.form1.tb_last_name.value.match(numericExpression) || (document.form1.tb_last_name.value == ""))
       {
    	alert("Please enter only letters for your last name.");
		document.form1.tb_last_name.focus();
		document.form1.tb_last_name.value = "";
        return false;
     }

    if (!document.form1.tb_mobile_phone1.value.match(numericExpression)||(document.form1.tb_mobile_phone1.value == ""))
      {
       alert("Please enter your area code for your phone number.");
       return false;
      }
      
       if (!document.form1.tb_mobile_phone2.value.match(numericExpression)||(document.form1.tb_mobile_phone2.value == ""))
      {
       alert("Please the prefix for your mobile phone number.");
       return false;
      }
        if (!document.form1.tb_mobile_phone3.value.match(numericExpression)||(document.form1.tb_mobile_phone3.value == ""))
      {
       alert("Please enter your mobile phone number.");
       return false;
      }
      
   if (document.form1.tb_mobile_carrier.value.length < 1)
      {
       alert("Please enter your mobile carrier.");
       return false;
      }  

      if (!document.form1.tb_email.value.match(emailExp)|| (document.form1.tb_email.value == "" ))
	{
		alert("Please enter a valid email address.");
		document.form1.tb_email.focus();
		document.form1.tb_email.value = "";
		return false;
	}
 if (document.form1.tb_address.value == "")
	{
		alert("Please enter your address.");
		return false;
	}
   
   if (document.form1.tb_city.value.length < 1)
      {
       alert("Please enter your city.");
       return false;
      }
      
   if (document.form1.tb_state.value.length < 1)
      {
       alert("Please enter your state's abbreviation.");
       return false;
      }
      

       if(document.form1.tb_zip.value.match(alphaExp) || (document.form1.tb_zip.value == "")){
    	alert("Please enter five digits for zip code.");
		document.form1.tb_zip.focus();
		document.form1.tb_zip.value = "";
        return false;
     }
     
    if(document.form1.tb_zip.value == "" ||(document.form1.tb_zip.value.length != 5)){
    	alert("Please enter five digits for zip code.");
		document.form1.tb_zip.focus();
		document.form1.tb_zip.value = "";
        return false;
     }
	
      
	//document.form1.submit();   
	return true;

}