function isValidEmail(strEmail){
			
			if(strEmail.length == 0) {
				return true;
			} else if (strEmail.length < 5) {
		             return false;
		       	}else{
		           	if (strEmail.indexOf(" ") > 0){
		                      	return false;
		               	}else{
		                  	if (strEmail.indexOf("@") < 1) {
		                            	return false;
		                     	}else{
		                           	if (strEmail.lastIndexOf(".") < (strEmail.indexOf("@") + 2)){
		                                     	return false;
		                                }else{
		                                        if (strEmail.lastIndexOf(".") >= strEmail.length-2){
		                                        	return false;
		                                        }
		                              	}
		                       	}
		              	}
		       	}
		      	return true;
			}	


						
		
			function checkFieldInput(field, errText)
			{
				var sizeNull = eval("document.sendform."+field+".value.length == 0;");
				if (sizeNull) {
					alert(errText);
					eval("document.sendform."+field+".focus();");
					return false;
				} 
				return true;
			}

			
			function submitmaterial()
			{
				
                 if (!checkFieldInput("navn","Indtast navn")) { return false };
				 if (!checkFieldInput("adresse","Indtast adresse")) { return false };
				 if (!checkFieldInput("postnr","Indtast postnr")) { return false };
				 if (!checkFieldInput("by","Indtast by")) { return false };
				 if (!checkFieldInput("email","Indtast e-mail adresse")) { return false };
				 if (document.sendform.email.value.length > 0 && !isValidEmail(document.sendform.email.value)) {
						alert('Indtast venligst en korrekt email-adresse');
						document.sendform.email.focus();
						return false;
					}

				document.sendform.submit();				
			}