diff --git a/src/app/scripts.ts b/src/app/scripts.ts
index 036d350..4b3f4e0 100644
--- a/src/app/scripts.ts
+++ b/src/app/scripts.ts
@@ -109,7 +109,7 @@ export function isInputValidRegex(obj: string | undefined, subj: string | undefi
   return true;
 }
 
-export function isInputFilled(obj: string | undefined, subj: string | undefined, bounds: string | undefined, vars: string | undefined) {
+export function isInputFilled(obj: string | undefined, subj: string | undefined, bounds: string | undefined, vars: string | undefined): boolean {
   // if empty input: fetching inputs
   if (obj == "" || subj == "" || bounds == "" || vars == "") {
     const objectiveElement = document.getElementById('objective');
@@ -281,7 +281,6 @@ export function downloadLPFormatting(objective: any, subject: any, bounds: any)
   return lpFormat;
 }
 
-
 function downloadProblemDownload(content: string) {
   customLog("downloadPrepFile");
   customLog("");
@@ -690,4 +689,4 @@ export function downloadMPS() {
   let mps = convertLPToMPS(lp);
 
   downloadProblemDownload(mps);
-}
\ No newline at end of file
+}