Modal field number remove issue

[reymesson1]

if(event.target.firstname.value.length==3){

                for(var x=0;x<nextStateCust.length;x++){

                    if(nextStateCust[x].telefono==this.state.tempNumber){
                    fullname=nextStateCust[x].name + ' ' + nextStateCust[x].apellido;
                    telefono=this.state.tempNumber
                    }
                }

                newItem = {

                    "id": Date.now(),
                    "firstname":fullname,
                    "telefono":this.state.tempNumber,
                    "item":event.target.suggest.value,
                    "itemDetail": this.state.detailAdded,
                    "development":event.target.development.value,
                    "quantity":event.target.quantity.value,
                    "project":project,
                } 

                console.log(newItem)
            }else{

                for(var x=0;x<nextStateCust.length;x++){

                    if(nextStateCust[x].telefono==event.target.firstname.value){
                    fullname=nextStateCust[x].name + ' ' + nextStateCust[x].apellido;
                    telefono=event.target.firstname.value
                    }
                }

                newItem = {

                    "id": Date.now(),
                    "firstname":fullname,
                    "telefono":event.target.firstname.value,
                    "item":event.target.suggest.value,
                    "itemDetail": this.state.detailAdded,
                    "development":event.target.development.value,
                    "quantity":event.target.quantity.value,
                    "project":project,
                }
            }

[reymesson1]

class master

[reymesson1]

        tempNumber: ''