function won't run the second part of the code how do i fix this? : Here is my code

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

    function CheckForm_1(){
    	var F1 = document.getElementById('srch');
    	var Lgth = document.getElementById('srch');
    		if(F1.value == ""){
    			document.getElementById("Empty_Err");
    				Empty_Err.style.display = 'inline';
    				Empty_Err.stylebackgroundColor = 'linen';
    					return false;
    		}else{
    			return true;
    		}
    	if(Lgth.value.length > 17 || Lgth.value.length < 4){
    			document.getElementById("Length_Err");
    			Length_Err.style.display = 'inline';
    			backgroundColor = 'linen';
    			alert("Search length must be be between 4 and 17");
    		return false;
    	}else{
    		return true;
    	}	
    }

<!-- end snippet -->

I can't get it to check the field length Any ideas on this?
The code will run a check for an empty field just fine.