Nesting issue while duplicating functions

function regchk()
	{	
	  frm=document.myform;
	  
		 if(frm.fname.value=="")
		{
		alert("Please enter your first and last name");
		frm.fname.focus();
		return false;
		}
		 if(frm.lname.value=="")
		{
		alert("Please enter your first and last name");
		frm.lname.focus();
		return false;
		}
		
		if(frm.em.value=="")
		{
		alert("Please enter your email address");
		frm.em.focus();
		return false;
		}
		else
		{
			if(!emailInvalid(frm.em.value))
			{
				alert("Please enter a valid email address");
				frm.em.focus();
				return false;
			}
		}
		
		if(frm.ptcity.value=="")
		{
		alert("Please enter your city");
		frm.ptcity.focus();
		return false;
		}
		
		if(frm.st.value=="")
		{
		alert("Please enter your state");
		frm.st.focus();
		return false;
		}
		
		if(frm.zip.value=="")
		{
		alert("Please enter your zip code");
		frm.zip.focus();
		return false;
		}
		
		if(frm.pn.value=="")
		{
		alert("Please enter your phone number");
		frm.pn.focus();
		return false;
		}
 		
	if ( frm.agree.checked == false ) 
		{ 
		alert ( "You must agree to the Terms and Conditions and Privacy Policy to continue" ); 
		return false; 
		}
	}
	function emailInvalid(s)
{
	if(!(s.match(/^[\w]+([_|\.-][\w]{1,})*@[\w]{2,}([_|\.-][\w]{1,})*\.([a-z]{2,4})$/i) ))
        {
		return false;
		
	}
	else
		return true;
} 

if(!phoneInvalid(frm.em.value))
			{
				alert("Please enter 10 digits for the phone number");
				frm.pn.focus();
				return false;
			}



	function phoneInvalid(s)
{
	if(phone.length != 10) { 
   alert("please enter 10 digits for the phone number");
        {
		return false;	
	}