function f_login(){
	var m_message= "You must enter"
	var m_message1= ""
	var m_message2= ""
	var m_check= 0
	var name_pass= 0
	if (document.log_form.u_username.value==""){
		m_message+= " your username";
		m_check= 1;
	}
	if (document.log_form.u_password.value==""){
		if (m_check== 0){
			m_message+= " your password";
			m_check= 1;	
		}
		else{
			m_message1= " and your password"
			m_message2= ", password"
			m_check= 2
		}		
	}
	
			
	if (m_check> 0){
		
		if (m_check= 1){
			m_message+= m_message1+ ".";
			
		}
		else{
			m_message+= m_message1+ m_message2+ "."
		}
		alert(m_message);
	}
	else{
		//Username and password filled in, now check username and password.
		
		if (document.log_form.u_username.value!="EMAAtlanta"){
			name_pass= 1
		}
		else {
			if (document.log_form.u_password.value=="safety"){
				//submit form
				//Return(true)
				//document.log_form.submit();
				location.href='ema.html'
			}
			else{
				name_pass= 1
			}
		
		}
	}
	if (name_pass== 1){
		alert("User name or password invaild")
	}
}