Javascript don't work
help me. my code js may wrong any where. Code Js var uutien=0; //ghi nho so hang var arrayindex=0; var arrayphantu= new Array(); //mang ghi nho phep tinh var arraycal_index=0; var arraycal= new Array(); //ghi nho dau var dau=false; var button_new=""; //event function clickBut(obj){ var ketqua=document.getElementById("ketqua"); var str_ketqua_old=ketqua.value; if(str_ketqua_old==0){ str_ketqua_old=""; } var type = obj.innerHTML; //alert(type); if ( type=="0" || type =="1" || type=="2" || type=="3" || type=="4" || type=="5" || type=="6" || type=="7" || type=="8" || type=="9" || type=="+/-" || type==".") { if (type=="+/-"){ if(dau){ dau=false; button_new=button_new.substring(1); }else{dau=true; button_new="-" + button_new;} }else{ button_new+=type; } ketqua.value=str_ketqua_old+ button_new; } }